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 A024277 #17 Apr 02 2017 15:34:27 %S A024277 0,1,-6,176,-8176,691456,-86186496,15358324736,-3667315849216, %T A024277 1135407181398016,-441731548179726336,211079248633366839296, %U A024277 -121507103129359646457856,82940335057202543199256576 %N A024277 E.g.f.: log(1+tanh(x)*tan(x))/2 (even powers only). %e A024277 log(1+tanh(x)*tan(x))/2 = 1/2*x^2 - 1/4*x^4 + 11/45*x^6 - 73/360*x^8 +- ... . %t A024277 Log[ 1+Tanh[ x ]*Tan[ x ]]/2 (* Even Part *) %Y A024277 Cf. A009398. %Y A024277 Cf. A101921. %K A024277 sign %O A024277 0,3 %A A024277 _R. H. Hardin_ %E A024277 Extended with signs Mar 1997