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 A296194 #20 Feb 16 2025 08:33:52
%S A296194 0,1,12,162,3010,81000,3105396,162469104,11117235312,961808277600,
%T A296194 102496397652000,13180200302839680,2011319092988899200,
%U A296194 359224661189539192320,74214101648670824736000,17557926151618710547200000,4715558231100365363023411200
%N A296194 Harary index of the n-transposition graph.
%H A296194 Andrew Howroyd, <a href="/A296194/b296194.txt">Table of n, a(n) for n = 1..100</a>
%H A296194 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HararyIndex.html">Harary Index</a>
%H A296194 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TranspositionGraph.html">Transposition Graph</a>
%F A296194 a(n) = (n!/2) * Sum_{k=1..n-1} abs(Stirling1(n, n-k))/k. - _Andrew Howroyd_, Dec 09 2017
%t A296194 Table[n! Sum[((-1)^k StirlingS1[n, n - k])/k, {k, n - 1}]/2, {n, 20}]
%o A296194 (PARI) a(n)={n!*sum(k=1, n-1, abs(stirling(n, n-k, 1))/k)/2} \\ _Andrew Howroyd_, Dec 09 2017
%Y A296194 Cf. A292062.
%K A296194 nonn
%O A296194 1,3
%A A296194 _Eric W. Weisstein_, Dec 07 2017
%E A296194 Terms a(9) and beyond from _Andrew Howroyd_, Dec 09 2017