%I #4 Sep 25 2017 07:07:14

%S 1,1,5,1,1,1,13,5,17,17,1,1,25,5,29,29,29,5,37,481,1517,41,205,41,1,

%T 17,901,265,53,53,3233,61,3965,61,61,1,73,1825,365,73,73,73,85,493,

%U 2581,33553,89,445,8633,8633,871933,871933,48985,9797,1067873,39511301,46028629,230143145

%N a(n) = denominator of Atkin polynomials A_n(j) evaluated at j = 1728.

%H M. Kaneko and D. Zagier, <a href="http://www2.math.kyushu-u.ac.jp/~mkaneko/papers/atkin.pdf">Supersingular j-invariants, hypergeometric series and Atkin's orthogonal polynomials</a>, pp. 97-126 of D. A. Buell and J. T. Teitelbaum, eds., Computational Perspectives on Number Theory, Amer. Math. Soc., 1998

%F See Maple code for formula.

%e 1008, 421344, 901254816/5, 77507914176, 33392993024160, 14400272882673216, 80771130598914068544/13, ...

%p af:=proc(a,n) mul(a+i,i=0..n-1); end; A1728:=n->-12^(3*n+1)*af(-1/12,n)*af(7/12,n)/(2*n-1)!;

%Y Cf. A145235, A145093.

%K nonn,frac

%O 1,3

%A _N. J. A. Sloane_, Feb 28 2009