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 A065068 #24 Jul 03 2025 18:21:42 %S A065068 1,2,6,17,45,114,264,545,1061,2070,3990,7275,12556,20824,33584,52753, %T A065068 80560,119274,170168,232700,306472,396580,517300,688736,926816, %U A065068 1241720,1640968,2130448,2710356,3383596,4171788,5120776,6289760,7747928,9582196,11908872,14887792,18732340,23712492,30141180,38341172,48622328,61275752,76578628,94786504,116132688,140870564,169379536,202262720,240326780,284337040,334532714,389976092 %N A065068 Number of fixed polyominoes with n cells of which no four are equally spaced on a straight line. %C A065068 a(142) = 36 is the final nonzero term of this sequence. - _Jan Kristian Haugland_, Apr 28 2020 %H A065068 Jan Kristian Haugland, <a href="/A065068/a065068.gif">Illustration for n = 142</a> [Cached copy, with permission] %H A065068 J. K. Haugland, <a href="https://arxiv.org/abs/2004.12801">Largest polyomino with no four cells equally spaced on a straight line</a>, arXiv:2004.12801 [math.GM] (2020). %H A065068 Wikipedia, <a href="https://en.wikipedia.org/wiki/Polyomino">Polyomino</a> %F A065068 a(n) = 0 for n >= 143. - _Jan Kristian Haugland_, Apr 28 2020 %Y A065068 Cf. A001168. %K A065068 nonn %O A065068 1,2 %A A065068 _Jan Kristian Haugland_, Nov 07 2001 %E A065068 a(32)-a(53) from Brendan Owen (brendan_owen(AT)yahoo.com), Mar 11 2002