A241453 a(n) = pg(3, n) * pg(4, n) * ... * pg(n, n) where pg(m, n) is the n-th m-th-order polygonal number.

1, 1, 1, 6, 160, 13125, 2544696, 978839680, 662561095680, 724201891583625, 1198933986250000000, 2861518844725337212416, 9468599329204035806822400, 42083045149004715366557171125, 244738882349978781346230604032000, 1821980763196818488550000000000000000

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..100

Wikipedia, Polygonal number

Example

a(5) = pg(3, 5) * pg(4, 5) * pg(5, 5) = 15 * 25 * 35 = 13125.

Maple

p:= (s, n)-> (n^2*(s-2)-n*(s-4))/2:
a:= n-> mul(p(i, n), i=3..n):
seq(a(n), n=0..15);  # Alois P. Heinz, Apr 23 2014

Prog

(PARI) pg(m, n) = (n^2*(m-2)-n*(m-4))/2;
v=[]; for(n=0, 20, v=concat(v, prod(m=3, n, pg(m, n)))); v

Crossrefs

Cf. A241452.

Sequence in context: A030449 A364370 A120277 * A193370 A332116 A015086

Adjacent sequences: A241450 A241451 A241452 * A241454 A241455 A241456

Keyword

nonn

Author

Colin Barker, Apr 22 2014

Status

approved