cp's OEIS Frontend

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.

A014608 a(n) = (4n)!/(24^n).

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%I A014608 #21 Jan 26 2022 03:20:41
%S A014608 1,1,70,34650,63063000,305540235000,3246670537110000,
%T A014608 66475579247327250000,2390461829733887910000000,
%U A014608 140810154080474667338550000000,12868639981414579848070084500000000,1746930746117010628955362040959500000000
%N A014608 a(n) = (4n)!/(24^n).
%C A014608 a(n) is also the constant term in product 1 <= i,j <= n, i different from j (1 - x_i/x_j)^4. - Sharon Sela (sharonsela(AT)hotmail.com), Feb 16 2002
%D A014608 George E. Andrews, Richard Askey and Ranjan Roy, Special Functions, Cambridge University Press, 1998.
%H A014608 Alois P. Heinz, <a href="/A014608/b014608.txt">Table of n, a(n) for n = 0..130</a>
%H A014608 J.-C. Novelli and J.-Y. Thibon, <a href="http://arxiv.org/abs/1403.5962">Hopf Algebras of m-permutations,(m+1)-ary trees, and m-parking functions</a>, arXiv preprint arXiv:1403.5962 [math.CO], 2014-2020.
%F A014608 From _Amiram Eldar_, Jan 26 2022: (Start)
%F A014608 Sum_{n>=0} 1/a(n) = (cos(2^(3/4)*3^(1/4)) + cosh(2^(3/4)*3^(1/4)))/2.
%F A014608 Sum_{n>=0} (-1)^n/a(n) = cos(6^(1/4))*cosh(6^(1/4)). (End)
%t A014608 Table[(4n)!/24^n,{n,0,10}] (* _Harvey P. Dale_, Oct 15 2015 *)
%o A014608 (PARI) a(n)=(4*n)!/24^n;
%Y A014608 Cf. A000680, A014606.
%K A014608 nonn
%O A014608 0,3
%A A014608 BjornE (mdeans(AT)algonet.se)