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 A002684 M4307 N1802 #18 Dec 20 2021 20:20:32 %S A002684 6,360,10080,259200,239500800,145297152000,15692092416000, %T A002684 16005934264320000,8515157028618240000,3372002183332823040000, %U A002684 4653363012999295795200000,8469120683658718347264000000 %N A002684 Denominators of coefficients for repeated integration. %D A002684 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A002684 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A002684 H. E. Salzer, <a href="https://doi.org/10.1002/sapm194928154">Coefficients for repeated integration with central differences</a>, Journal of Mathematics and Physics, 28 (1949), 54-61. %F A002684 a(n) is the denominator of -(n/2)M(n)-(2n+2)M(n+1), where M(n)=(2/(2n+1)!)*int(t*product(t^2-k^2, k=1..n), t=0..1). - _Emeric Deutsch_, Jan 25 2005 %p A002684 M:=n->(2/(2*n+1)!)*int(t*product(t^2-k^2,k=1..n),t=0..1):B:=n->-(n/2)*M(n)-(2*n+2)*M(n+1): seq(denom(B(n)),n=0..13); # _Emeric Deutsch_, Jan 25 2005 %Y A002684 Cf. A002195, A002196, A002683. %K A002684 nonn,frac %O A002684 0,1 %A A002684 _N. J. A. Sloane_ %E A002684 More terms from _Emeric Deutsch_, Jan 25 2005