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 A289988 #25 Jun 02 2025 17:08:27
%S A289988 1,1,2,4,37,602,34126,6021463,3616906549,7361925161868,
%T A289988 51324462383008758,1240420936122453106498,105141919479926837860474091,
%U A289988 31581183353539008502807807352728
%N A289988 Number of unlabeled connected loopless multigraphs with n nodes of degree n or less.
%C A289988 Multigraphs are loopless.
%o A289988 (nauty) for n in {1..8}; do geng -c -D${n} ${n} -q | multig -m$[${n}-1] -D$[${n}-1] -u; done
%Y A289988 Main diagonal of A334546.
%Y A289988 Cf. A007719, A076864, A134818, A289157, A289158, A289987.
%K A289988 nonn,more
%O A289988 0,3
%A A289988 _Natan Arie Consigli_, Aug 19 2017
%E A289988 a(0) corrected and a(9)-a(13) from _Andrew Howroyd_, May 05 2020