A001525 a(n) = (3n)!/(3!n!).

1, 60, 10080, 3326400, 1816214400, 1482030950400, 1689515283456000, 2564684200286208000, 5001134190558105600000, 12182762888199545241600000, 36255902355281846639001600000, 129433571408356192501235712000000, 545950804200446419970212233216000000

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• T. D. Noe, Table of n, a(n) for n = 1..100

Crossrefs

Equals A064350/3!, row sums of A157704/3! and row sums of A157705/3!.

Programs

Mathematica

Table[(3 n)!/(3! n!), {n, 20}] (* Harvey P. Dale, May 25 2011 *)

Extensions

More terms from Harvey P. Dale, May 25 2011