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 A013325 #7 Mar 27 2021 18:30:16 %S A013325 1,-1,-1,-359,-1681,-52981,-1887113,-27492467,-3259141,-1194145112779, %T A013325 -55919619312049,-7462251938940527,-113201511292945547, %U A013325 -1055956853774285077,-44032898634010565651,-75833822693358307239889 %N A013325 Numerator of [x^n] in the Taylor series arccosh(exp(x)-arctanh(x))= x-x^2/6-x^3/72 -359*x^4/2160 -1681*x^5/51840 -52981*x^6/435456 -... %C A013325 The inner function exp(x)-arctanh(x) = 1+x^2/2! -x^3/3! +x^4/4! -23*x^5/120 + x^6/6! -719*x^7/7!.. has e.g.f. coefficients apparently closely related to A127230. %K A013325 sign,frac %O A013325 1,4 %A A013325 Patrick Demichel (patrick.demichel(AT)hp.com) %E A013325 Values replaced by numerators. - _R. J. Mathar_, Dec 22 2011