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 A121293 #18 Nov 05 2015 02:41:28
%S A121293 2,52,4140,678570,190899322,82864869804,51724158235372,
%T A121293 44152005855084346,49631246523618756274,71339801938860275191172,
%U A121293 128064670049908713818925644,281600203019560266563340426570,746289892095625330523099540639146
%N A121293 a(n) = Bell(3*n+2).
%C A121293 Even Bell numbers. A000110 except A134715. - _Vladimir Reshetnikov_, Nov 02 2015
%H A121293 Robert Israel, <a href="/A121293/b121293.txt">Table of n, a(n) for n = 0..190</a>
%F A121293 E.g.f.: exp(-1)*Sum_{n>=0}(n^2*exp(n^3*x)/n!).
%p A121293 seq(combinat:-bell(3*k+2), k=0..20); # _Robert Israel_, Nov 02 2015
%t A121293 Table[ BellB[3*n + 2], {n, 0, 10}] (* _Jean-François Alcover_, Dec 13 2012 *)
%o A121293 (PARI) a000110(n) = n!*polcoeff(exp(exp(x+x*O(x^n))-1), n);
%o A121293 vector(20, n, n--; a000110(3*n+2)) \\ _Altug Alkan_, Nov 02 2015
%Y A121293 Cf. A000110, A070906, A134715.
%K A121293 easy,nonn
%O A121293 0,1
%A A121293 _Vladeta Jovovic_, Aug 24 2006