%I #22 Apr 19 2024 02:12:01
%S 0,1,15,495,29295,2735775,370945575,68916822975,16813959537375,
%T 5214921734397375,2004231846526284375,934957186489800849375,
%U 520444368391989625959375,340788940288324502208609375,259324006920606914270844234375,226933251813970116856323617109375,226305693647403205116652558922109375
%N a(n) = (2*n)! - ((2*n-1)!!)^2.
%C This was (incorrectly) proposed as a formula for A001818(2n).
%H Tewodros Amdeberhan, Adriana Duncan, Victor H. Moll, and Vaishavi Sharma, <a href="https://arxiv.org/abs/2012.05040">Filter integrals for orthogonal polynomials</a>, arXiv:2012.05040 [math.CA], 2020.
%F a(n) = A000142(2*n) - A001147(n)^2.
%F a(n) = A010050(n) - A001818(n).
%p seq((2*n)! - doublefactorial(2*n-1)^2, n=0..16); # _Georg Fischer_, Apr 19 2024
%Y Cf. A000142, A010050, A001147, A001818.
%Y Bisection of A088979.
%K nonn
%O 0,3
%A _N. J. A. Sloane_, Jul 03 2009
%E Definition corrected by _Georg Fischer_, Apr 18 2024
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