A115242 Sequence of iterated increasing power sums. These sums are a generalization of iterated triangle sums.

1, 15, 131325321, 210449029945495266124836624698709415244045199778210143675

Offset

1,2

Comments

These are iterated increasing power sums. These sums are a generalization of iterated triangle sums.

Links

Table of n, a(n) for n=1..4.

Formula

Let S(m, n) = Sum_{k=1...n} k^m; we define a(1):=S(1, 1), a(2):=S(1, S(2, 2)) etc., a(n):=S(1, S(2, S(3, ...S(n, n))...))).

Example

a(1) = S(1,1) = 1.
a(2) = S(1,S(2,2)) = S(1,5) = 15.
a(3) = S(1,S(2,S(3,3))) = S(1,S(2,36)) = S(1,16206) = 131325321.

Crossrefs

See A113776 for iterated decreasing power sums.

Sequence in context: A084878 A013874 A068252 * A296528 A072723 A111413

Adjacent sequences: A115239 A115240 A115241 * A115243 A115244 A115245

Keyword

nonn

Author

Hieronymus Fischer, Jan 19 2006

Status

approved