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 A007480 M5028 #25 Apr 10 2017 12:36:28
%S A007480 1,16,1296,20736,12960000,12960000,31116960000,497871360000,
%T A007480 40327580160000,40327580160000,590436101122560000,590436101122560000,
%U A007480 16863445484161436160000,16863445484161436160000,16863445484161436160000,269815127746582978560000
%N A007480 a(n) = denominator of sum_{k=1..n} k^(-4).
%D A007480 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A007480 T. D. Noe, <a href="/A007480/b007480.txt">Table of n, a(n) for n=1..200</a>
%H A007480 D. Y. Savio, E. A. Lamagna and S.-M. Liu, <a href="http://dx.doi.org/10.1007/978-1-4613-9647-5_2">Summation of harmonic numbers</a>, pp. 12-20 of E. Kaltofen and S. M. Watt, editors, Computers and Mathematics, Springer-Verlag, NY, 1989.
%F A007480 a(n) = denominator of (Pi^4/90 - zeta(4, n+1)). - _Arkadiusz Wesolowski_, Nov 23 2012
%F A007480 Denominators of coefficients in expansion of PolyLog(4, x)/(1 - x). - _Ilya Gutkovskiy_, Apr 10 2017
%t A007480 Denominator[Accumulate[1/Range[20]^4]] (* _Harvey P. Dale_, Dec 25 2013 *)
%Y A007480 Cf. A007410.
%K A007480 nonn,easy,frac
%O A007480 1,2
%A A007480 _N. J. A. Sloane_, _Mira Bernstein_