A075221 - cp's OEIS frontend

A075221 Number of polyiamonds with n cells that tile the plane by translation or by 180-degree rotation (Conway criterion).

n	a(n)
1	1
2	1
3	1
4	3
5	4
6	12
7	21
8	56
9	111
10	262
11	462
12	1453
13	1875
14	4734
15	9410
16	20603
17	24034
18	79352
19	79925
20	273731
21	358096
22	669640
23	796571
24	3342349
25	2980476
26	6387513
27	10167660
28	24999509
29	21477012
30	87978317

[1, 1, 1, 3, 4, 12, 21, 56, 111, 262, 462, 1453, 1875, 4734, 9410, 20603, 24034, 79352, 79925, 273731, 358096, 669640, 796571, 3342349, 2980476, 6387513, 10167660, 24999509, 21477012, 87978317]

cp's OEIS Frontend

A075221 Number of polyiamonds with n cells that tile the plane by translation or by 180-degree rotation (Conway criterion).

Table of values

List of values