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 A350681 #15 Jan 12 2022 21:36:50 %S A350681 1,0,0,0,1,0,0,1,1,0,0,1,2,1,0,0,1,4,4,1,0,0,1,8,11,8,1,0,0,1,16,27, %T A350681 27,16,1,0,0,1,32,64,76,64,32,1,0 %N A350681 Triangle read by rows. T(n,k) is the number of hitomezashi loops of width 2(n-k)+1 and height 2k+1 for 0 <= k <= n. %C A350681 The Defant--Kravitz paper proves that every hitomezashi loop has odd width and odd height. %H A350681 Colin Defant and Noah Kravitz, <a href="https://arxiv.org/abs/2201.03461">Loops and Regions in Hitomezashi Patterns</a>, arXiv:2201.03461 [math.CO], 2022. %F A350681 T(n,k) = T(n,n-k). %e A350681 Triangle T(n,k) begins: %e A350681 1; %e A350681 0, 0; %e A350681 0, 1, 0; %e A350681 0, 1, 1, 0; %e A350681 0, 1, 2, 1, 0; %e A350681 0, 1, 4, 4, 1, 0; %e A350681 0, 1, 8, 11, 8, 1, 0; %e A350681 0, 1, 16, 27, 27, 16, 1, 0; %e A350681 0, 1, 32, 64, 76, 64, 32, 1, 0; %e A350681 ... %Y A350681 T(2n,n) gives: A350680. %K A350681 nonn,tabl,more %O A350681 0,13 %A A350681 _Colin Defant_, Jan 11 2022