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 A345076 #17 Jun 06 2025 05:30:03 %S A345076 1,2,3,5,13,32,96,283,907,2929,9787,32939,112476,386230,1336150, %T A345076 4642930,16208851,56786242,199614651,703678568,2487109359,8811020024, %U A345076 31281360326,111272475650 %N A345076 Number of generalized polyforms on the elongated triangular tiling with n cells. %C A345076 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 A345076 Peter Kagey, <a href="/A345076/a345076.pdf">The a(3) = 5 generalized polyforms on the elongated triangular tiling with 3 cells</a>. %H A345076 Wikipedia, <a href="https://en.wikipedia.org/wiki/Elongated_triangular_tiling">Elongated Triangular Tiling</a> %e A345076 See the PDF in the links section. %Y A345076 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 A345076 nonn,more %O A345076 0,2 %A A345076 _Drake Thomas_, Jun 07 2021 %E A345076 a(15)-a(23) from _Bert Dobbelaere_, Jun 05 2025