A260231 - OEIS

A260231

a(n) = Product_{k=1..n} (1 + k^k).

2, 10, 280, 71960, 224946960, 10495350312720, 8643382777938679680, 145011908479540041684850560, 56180584638978557924165229531974400, 561805846445966163880630853243909229531974400, 160289764609087349005207761687490741791453382934816332800

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..11.

FORMULA

a(n) ~ c * A002109(n), where c = Product_{k>=1} (1 + 1/k^k) = 2.60361190459951423330221282635022049352582879064202503882732200701325334...

MATHEMATICA

Table[Product[1+k^k, {k, 1, n}], {n, 1, 12}]

CROSSREFS

Cf. A000312, A002109, A028361, A054640, A082480, A217757, A258325.

Sequence in context: A206158 A144288 A215286 * A003047 A028580 A171873

Adjacent sequences: A260228 A260229 A260230 * A260232 A260233 A260234

KEYWORD

nonn

AUTHOR

Vaclav Kotesovec, Jul 20 2015

STATUS

approved