%I A001421
%S A001421 1,120,83160,81681600,93699005400,117386113965120,155667030019300800,
%T A001421 214804163196079142400,305240072216678400087000,
%U A001421 443655767845074392936328000,656486312795713480715743268160
%N A001421 (6*n)!/((n!)^3*(3*n)!).
%D A001421 M. Kaneko and D. Zagier, Supersingular j-invariants, hypergeometric series 
               and Atkin's orthogonal polynomials, pp. 97-126 of D. A. Buell and 
               J. T. Teitelbaum, eds., Computational Perspectives on Number Theory, 
               Amer. Math. Soc., 1998. (See Eq. 31.)
%F A001421 o.g.f.: Hypergeometric2F1(5/12, 1/12; 1; 1728x)^2 [From Jacob Lewis (jacobml(AT)uw.edu), 
               Jul 28 2009]
%p A001421 f := n->(6*n)!/( (n!)^3*(3*n)!);
%t A001421 Factorial[6 n]/(Factorial[3n] Factorial[n]^3) [From Jacob Lewis (jacobml(AT)uw.edu), 
               Jul 28 2009]
%Y A001421 Sequence in context: A074653 A065961 A058528 this_sequence A107446 A159735 
               A157879
%Y A001421 Adjacent sequences: A001418 A001419 A001420 this_sequence A001422 A001423 
               A001424
%K A001421 nonn
%O A001421 0,2
%A A001421 N. J. A. Sloane (njas(AT)research.att.com), KUPK78A(AT)prodigy.com (Glenn 
               K Painter)