Notes on Polyiamonds

Author: David Goodger <goodger@python.org>
Date: 2016-12-05
Revision: 644
Web site:http://puzzler.sourceforge.net/
Copyright: © 1998-2016 by David J. Goodger
License:GPL 2
images/puzzler.png

Contents

Polyform Counts

Units are equilateral triangles.

Order Name Free Units Sum One-sided Units Sum
1 moniamond 1 1 1 1 1 1
2 diamond 1 2 3 1 2 3
3 triamond 1 3 6 1 3 6
4 tetriamond 3 12 18 4 16 22
5 pentiamond 4 20 38 6 30 52
6 hexiamond 12 72 110 19 114 166
7 heptiamond 24 168 278 43 301 467
8 octiamond 66 528 806 120 960 1427

Parity Data

In the table below, the "Min-D" and "Max-D" columns record, respectively, the minimum and maximum disparities that can be supported by these polyiamonds: the minimum and maximum discrepancies in parity of the puzzle's unit triangles, i.e. the minimum and maximum differences between the number of z=0 and z=1 triangles.

Order Name Free Units Min-D Max-D One-sided Units Min-D Max-D
1 moniamond 1 1 1 1 1 1 1 1
2 diamond 1 2 0 0 1 2 0 0
3 triamond 1 3 1 1 1 3 1 1
4 tetriamond 3 12 2 2 4 16 2 2
5 pentiamond 4 20 0 4 6 30 0 6
6 hexiamond 12 72 0 4 19 114 0 8
7 heptiamond 24 168 0 26 43 301 1 45
8 octiamond 66 528 ? ? 120 960 ? ?

Shapes

Triangles:

T(n) = n²

Hexagons:

H(n) = 6T(n) = 6n²

Hexagrams:

Hg(n) = H(n) + 6T(n)
      = 2H(n)
      = 12n²
n n-Triangle n-Hexagon n-Hexagram
1 1 6 12
2 4 24 48
3 9 54 108
4 16 96 192
5 25 150 300
6 36 216 432
7 49 294 588
8 64 384 768
9 81 486 972
10 100 600 1200
11 121 726 1452
12 144 864 1728
13 169 1014 2028
14 196 1176 2352
15 225 1350 2700
16 256 1536 3072
17 289 1734 3468
18 324 1944 3888
19 361 2166 4332
20 400 2400 4800
21 441 2646 5292
22 484 2904 5808
23 529 3174 6348
24 576 3456 6912

Parallelograms:

P(m,n) = 2mn
P m=1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
n=1 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
2 ... 8 12 16 20 24 28 32 36 40 44 48 52 56 60
3 ... ... 18 24 30 36 42 48 54 60 66 72 78 84 90
4 ... ... ... 32 40 48 56 64 72 80 88 96 104 112 120
5 ... ... ... ... 50 60 70 80 90 100 110 120 130 140 150
6 ... ... ... ... ... 72 84 96 108 120 132 144 156 168 180
7 ... ... ... ... ... ... 98 112 126 140 154 168 182 196 210
8 ... ... ... ... ... ... ... 128 144 160 176 192 208 224 240
9 ... ... ... ... ... ... ... ... 162 180 198 216 234 252 270
10 ... ... ... ... ... ... ... ... ... 200 220 240 260 280 300
11 ... ... ... ... ... ... ... ... ... ... 242 264 286 308 330
12 ... ... ... ... ... ... ... ... ... ... ... 288 312 336 360
13 ... ... ... ... ... ... ... ... ... ... ... ... 338 364 390
14 ... ... ... ... ... ... ... ... ... ... ... ... ... 392 420
15 ... ... ... ... ... ... ... ... ... ... ... ... ... ... 450

Trapezoids:

Tr(m,n) = P(m,n) - T(n)
        = 2mn - n²
Tr m=2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
n=1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31
2 ... 8 12 16 20 24 28 32 36 40 44 48 52 56 60
3 ... ... 15 21 27 33 39 45 51 57 63 69 75 81 87
4 ... ... ... 24 32 40 48 56 64 72 80 88 96 104 112
5 ... ... ... ... 35 45 55 65 75 85 95 105 115 125 135
6 ... ... ... ... ... 48 60 72 84 96 108 120 132 144 156
7 ... ... ... ... ... ... 63 77 91 105 119 133 147 161 175
8 ... ... ... ... ... ... ... 80 96 112 128 144 160 176 192
9 ... ... ... ... ... ... ... ... 99 117 135 153 171 189 207
10 ... ... ... ... ... ... ... ... ... 120 140 160 180 200 220
11 ... ... ... ... ... ... ... ... ... ... 143 165 187 209 231
12 ... ... ... ... ... ... ... ... ... ... ... 168 192 216 240
13 ... ... ... ... ... ... ... ... ... ... ... ... 195 221 247
14 ... ... ... ... ... ... ... ... ... ... ... ... ... 224 252
15 ... ... ... ... ... ... ... ... ... ... ... ... ... ... 255

Elongated hexagons:

He(m,n) = 2P(m,n) + 2T(n)
        = 4mn + 2n²
        = 2n(2m + n)
He m=1 2 3 4 5 6 7 8 9 10 11 12 13 14
n=1 6 10 14 18 22 26 30 34 38 42 46 50 54 58
2 16 24 32 40 48 56 64 72 80 88 96 104 112 120
3 30 42 54 66 78 90 102 114 126 138 150 162 174 186
4 48 64 80 96 112 128 144 160 176 192 208 224 240 256
5 70 90 110 130 150 170 190 210 230 250 270 290 310 330
6 96 120 144 168 192 216 240 264 288 312 336 360 384 408
7 126 154 182 210 238 266 294 322 350 378 406 434 462 490
8 160 192 224 256 288 320 352 384 416 448 480 512 544 576
9 198 234 270 306 342 378 414 450 486 522 558 594 630 666
10 240 280 320 360 400 440 480 520 560 600 640 680 720 760
11 286 330 374 418 462 506 550 594 638 682 726 770 814 858
12 336 384 432 480 528 576 624 672 720 768 816 864 912 960
13 390 442 494 546 598 650 702 754 806 858 910 962 1014 1066
14 448 504 560 616 672 728 784 840 896 952 1008 1064 1120 1176
15 510 570 630 690 750 810 870 930 990 1050 1110 1170 1230 1290

Semiregular hexagons:

Hs(m,n) = T(m+2n) - 3T(n)
        = m² + 4mn + 4n² - 3n²
        = m² + 4mn + n²
Hs m=2 3 4 5 6 7 8 9 10 11 12 13 14 15
n=1 13 22 33 46 61 78 97 118 141 166 193 222 253 286
2 ... 37 52 69 88 109 132 157 184 213 244 277 312 349
3 ... ... 73 94 117 142 169 198 229 262 297 334 373 414
4 ... ... ... 121 148 177 208 241 276 313 352 393 436 481
5 ... ... ... ... 181 214 249 286 325 366 409 454 501 550
6 ... ... ... ... ... 253 292 333 376 421 468 517 568 621
7 ... ... ... ... ... ... 337 382 429 478 529 582 637 694
8 ... ... ... ... ... ... ... 433 484 537 592 649 708 769
9 ... ... ... ... ... ... ... ... 541 598 657 718 781 846
10 ... ... ... ... ... ... ... ... ... 661 724 789 856 925
11 ... ... ... ... ... ... ... ... ... ... 793 862 933 1006
12 ... ... ... ... ... ... ... ... ... ... ... 937 1012 1089
13 ... ... ... ... ... ... ... ... ... ... ... ... 1093 1174
14 ... ... ... ... ... ... ... ... ... ... ... ... ... 1261

Chevrons:

C(m,n) = P(m,2n)
       = 4mn
C m=1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
n=1 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60
2 8 16 24 32 40 48 56 64 72 80 88 96 104 112 120
3 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180
4 16 32 48 64 80 96 112 128 144 160 176 192 208 224 240
5 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300
6 24 48 72 96 120 144 168 192 216 240 264 288 312 336 360
7 28 56 84 112 140 168 196 224 252 280 308 336 364 392 420
8 32 64 96 128 160 192 224 256 288 320 352 384 416 448 480
9 36 72 108 144 180 216 252 288 324 360 396 432 468 504 540
10 40 80 120 160 200 240 280 320 360 400 440 480 520 560 600
11 44 88 132 176 220 264 308 352 396 440 484 528 572 616 660
12 48 96 144 192 240 288 336 384 432 480 528 576 624 672 720
13 52 104 156 208 260 312 364 416 468 520 572 624 676 728 780
14 56 112 168 224 280 336 392 448 504 560 616 672 728 784 840
15 60 120 180 240 300 360 420 480 540 600 660 720 780 840 900

Butterflies:

B(m,n) = 2Tr(m,n)
       = 4mn - 2n²
B m=2 3 4 5 6 7 8 9 10 11 12 13 14 15
n=1 6 10 14 18 22 26 30 34 38 42 46 50 54 58
2 ... 16 24 32 40 48 56 64 72 80 88 96 104 112
3 ... ... 30 42 54 66 78 90 102 114 126 138 150 162
4 ... ... ... 48 64 80 96 112 128 144 160 176 192 208
5 ... ... ... ... 70 90 110 130 150 170 190 210 230 250
6 ... ... ... ... ... 96 120 144 168 192 216 240 264 288
7 ... ... ... ... ... ... 126 154 182 210 238 266 294 322
8 ... ... ... ... ... ... ... 160 192 224 256 288 320 352
9 ... ... ... ... ... ... ... ... 198 234 270 306 342 378
10 ... ... ... ... ... ... ... ... ... 240 280 320 360 400
11 ... ... ... ... ... ... ... ... ... ... 286 330 374 418
12 ... ... ... ... ... ... ... ... ... ... ... 336 384 432
13 ... ... ... ... ... ... ... ... ... ... ... ... 390 442
14 ... ... ... ... ... ... ... ... ... ... ... ... ... 448

Potential Puzzles

Puzzles not otherwise noted below have not been implemented or solved.

Initial numbers are the counts of unit equilateral triangles in the puzzles.

6: polyiamonds of order 1 to 3

18: polyiamonds of order 1 to 4

22: one-sided polyiamonds of order 1 to 4

38: polyiamonds of order 1 to 5

52: one-sided polyiamonds of order 1 to 5

72: Hexiamonds

92: pentiamonds & hexiamonds

108: 18 of 19 one-sided hexiamonds

110: polyiamonds of order 1 to 6

114: One-sided hexiamonds

166: one-sided polyiamonds of order 1 to 6

168: Heptiamonds

278: polyiamonds of order 1 to 7

301: One-sided heptiamonds

467: one-sided polyiamonds of order 1 to 7