This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A344211 #26 Jun 06 2025 05:30:31 %S A344211 1,3,2,7,16,60,201,838,3407,14767,64200,284676,1269981,5715325, %T A344211 25854146,117576949,536918541,2461230475,11319321354,52212782646 %N A344211 Number of generalized polyforms on the rhombitrihexagonal tiling with n cells. %C A344211 This sequence counts "free" polyforms where holes are allowed. This means that two polyforms are considered the same if one is a rigid transformation (translation, rotation, reflection or glide reflection) of the other. %H A344211 Kadon Enterprises, <a href="https://www.gamepuzzles.com/birds-bees-album.pdf">Birds and Bees</a>. %H A344211 Peter Kagey, <a href="/A344211/a344211.pdf">Illustration of a(3) = 7</a>. %H A344211 George Sicherman, <a href="https://sicherman.net/bbcat/">Catalogue of Polybirds</a>. %H A344211 Wikipedia, <a href="https://en.wikipedia.org/wiki/Rhombitrihexagonal_tiling">Rhombitrihexagonal tiling</a> %H A344211 Livio Zucca, <a href="https://www.iread.it/lz/polymultiforms2.html">PolyTriForms</a>. %Y A344211 Analogous for other tilings: A000105 (square), A000228 (hexagonal), A000577 (triangular), A197156 (prismatic pentagonal), A197159 (floret pentagonal), A197459 (rhombille), A197462 (kisrhombille), A197465 (tetrakis square), A309159 (snub square), A343398 (trihexagonal), A343406 (truncated hexagonal), A343577 (truncated square). %K A344211 nonn,more,hard %O A344211 0,2 %A A344211 _Peter Kagey_, May 11 2021 %E A344211 a(11)-a(19) from _Bert Dobbelaere_, Jun 05 2025