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 A359524 #5 Jan 05 2023 11:05:05 %S A359524 1,4,25,107,448,1701,6216,21771,74339,248379 %N A359524 Number of free holey polyiamonds of n cells with simply-connected interiors. %F A359524 a(n) = A070764(n) - A359523(n). %Y A359524 Cf. A000577, A070764, A359520, A359523. %K A359524 nonn,more %O A359524 9,2 %A A359524 _John Mason_, Jan 05 2023