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 A185344 #28 Mar 18 2020 09:00:45 %S A185344 1,0,0,0,0,0,0,0,1,0,2,2,12,31,220,1606,16829,193900,2452820,32670332, %T A185344 456028489,6636066134,100135577994,1582718914660 %N A185344 Number of not necessarily connected 4-regular simple graphs on n vertices with girth at least 4. %H A185344 Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/E_girth_ge_4">Not necessarily connected k-regular graphs with girth at least 4</a> %H A185344 Jason Kimberley, <a href="/wiki/User:Jason_Kimberley/E_k-reg_girth_ge_g_index">Index of sequences counting not necessarily connected k-regular simple graphs with girth at least g</a> %F A185344 This sequence is the Euler transformation of A033886. %F A185344 a(n) = A033886(n) + A185244(n). %t A185344 A033886 = Cases[Import["https://oeis.org/A033886/b033886.txt", "Table"], {_, _}][[All, 2]]; %t A185344 (* EulerTransform is defined in A005195 *) %t A185344 EulerTransform[Rest @ A033886] (* _Jean-François Alcover_, Dec 04 2019, updated Mar 18 2020 *) %Y A185344 4-regular simple graphs with girth at least 4: A033886 (connected), A185244 (disconnected), this sequence (not necessarily connected). %Y A185344 Not necessarily connected k-regular simple graphs with girth at least 4: A185314 (any k), A185304 (triangle); specified degree k: A008484 (k=2), A185334 (k=3), this sequence (k=4), A185354 (k=5), A185364 (k=6). %K A185344 nonn,hard,more %O A185344 0,11 %A A185344 _Jason Kimberley_, Nov 03 2011