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 A049216 #22 Aug 13 2024 14:36:01
%S A049216 1,70,6384,804320,136804096,30459752960,8632830664704,
%T A049216 3041109959196672,1305140879116763136,670935549630120394752,
%U A049216 407240889859179425562624,288272814806050917816729600
%N A049216 Scaled coefficients of (arctanh x)^5.
%F A049216 E.g.f.: (arctanh x)^5 or (1-x^2)^-1 * (arctanh x)^4.
%F A049216 a(n) is coefficient of x^(2*n+5) in (arctanh x)^5, multiplied by (2*n+5)!/5!.
%F A049216 a(n) = (1/16 ) * Sum_{p=1..2*n+4} binomial(2*n+3,p-1)*Sum_{m=5..2*n+5} binomial(m,5)*abs(s(2*n+5,m))*((-p)^(m-5)+(-p)^(m-5)) where s(n,m) is Stirling number of first kind . - _Ammar Khatab_, Aug 13 2024
%e A049216 (arctanh x)^5 = x^5 + 5/3*x^7 + 19/9*x^9 + 457/189*x^11 + ...
%t A049216 a[n_] := SeriesCoefficient[ArcTanh[x]^5, {x, 0, 2n+5}]*(2n+5)!/5!;
%t A049216 a /@ Range[0, 11] (* _Jean-François Alcover_, Mar 26 2021 *)
%Y A049216 Cf. A049214, A049215, A049217.
%K A049216 nonn
%O A049216 0,2
%A A049216 Joe Keane (jgk(AT)jgk.org)