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 A385265 #13 Jun 25 2025 01:09:13 %S A385265 1,2,4,13,53,209,904,3963,17900,81745,378554,1768236,8327789,39471091, %T A385265 188145066,901117082,4334151970,20923370406,101341800704,492289834345 %N A385265 Number of edge-connected components of polygonal cells in the pinwheel tiling up to rotation of the tiling. %C A385265 These are "one-sided" polyforms because there are no reflectional symmetries of the pinwheel tiling. %C A385265 Here the "pinwheel tiling" is a tiling consisting of rectangular and square cells, and does not refer to non-periodic triangular tilings. %H A385265 Peter Kagey, <a href="/A385265/a385265.png">Illustration of the pinwheel tiling</a>. %H A385265 Peter Kagey, <a href="/A385265/a385265_1.png">Illustration of the a(4)=53 polyforms with 4 cells</a>. %Y A385265 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), A344211 (rhombitrihexagonal), A344213 (truncated trihexagonal), A383908 (snub trihexagonal), A385266 (basketweave). %K A385265 nonn,more,hard %O A385265 0,2 %A A385265 _Peter Kagey_ and _Bert Dobbelaere_, Jun 23 2025