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 A004150 #16 Feb 22 2025 19:14:23 %S A004150 1,1,1,2,5,61,16,272,5831,6397,12505,297353,5672072,65286322, %T A004150 189063991,2137573091,54121519391,679243568902,1445769784042, %U A004150 23821158888092,525732881173073,6904213508941594,10973139347884396,2532586056883245101,50968075536143541551 %N A004150 Euler numbers written backwards. %F A004150 a(n) = A004086(A000111(n)). - _Michel Marcus_, Apr 05 2014 %t A004150 IntegerReverse/@With[{nn=30},CoefficientList[Series[(1+Sin[x])/Cos[x],{x,0,nn}],x]*Table[k!,{k,0,nn}]] (* _Harvey P. Dale_, May 25 2023 *) %Y A004150 Cf. A000111, A004086. %K A004150 nonn,base %O A004150 0,4 %A A004150 _N. J. A. Sloane_ %E A004150 More terms from _Eric M. Schmidt_, Apr 04 2014