A014609 a(n) = (5n)!/(5!^n).

1, 1, 252, 756756, 11732745024, 623360743125120, 88832646059788350720, 28837919555681211870935040, 18975581770994682860770223800320, 23183587808948692737291767860055162880, 49120458506088132224064306071170476903628800

Offset: 0

Author

BjornE (mdeans(AT)algonet.se)

Keywords

• nonn

Comments

a(n) is also the constant term in product 1 <= i,j <= n, i different from j (1 - x_i/x_j)^5. - Sharon Sela (sharonsela(AT)hotmail.com), Feb 18 2002

References

• G. E. Andrews, R. Askey, and R. Roy, Special Functions, Cambridge University Press, 1998.

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..105
• J.-C. Novelli and J.-Y. Thibon, Hopf Algebras of m-permutations,(m+1)-ary trees, and m-parking functions, arXiv preprint arXiv:1403.5962 [math.CO], 2014-2020.

Crossrefs

Cf. A000680, A014606, A014608.

Programs

PARI

a(n)=if(n<0,0,(5*n)!/120^n)