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 A368757 #12 Feb 16 2025 08:34:06 %S A368757 0,6,34,112,336,652,1530,2752,3952,7606,11794,15096,24720,33998,36154, %T A368757 60928,79616,94660,128514,159600,174868,239806,290394,329568,413376, %U A368757 486934,547126,665392,772240,821076,1021194,1164800,1280636,1500358,1694690,1863288,2135376,2383518,2592154 %N A368757 Number of edges in the hyperoctahedral (or cocktail party) graph of order n. %C A368757 See A368755 and A368756 for images of the graphs. %H A368757 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CocktailPartyGraph.html">Cocktail Party Graph</a>. %F A368757 a(n) = A368755(n) + A368756(n) - 1 by Euler's formula. %Y A368757 Cf. A368755 (regions), A368756 (vertices), A368758 (k-gons), A129348, A193130, A282010. %K A368757 nonn %O A368757 1,2 %A A368757 _Scott R. Shannon_, Jan 04 2024