A279020 a(n) = unreduced numerator in Sum_{k=1..n} (-1)^(k-1)/k^k.

0, 1, 3, 85, 21652, 67690148, 3158065145088, 2600806474859606784, 43634288683151793919033344, 16904817514490272003065681518985216, 169048175123324778807714958980684133171200000, 48231417258392463006590622244366007983063473271603200000

Offset

0,3

Links

Daniel Suteu, Table of n, a(n) for n = 0..19

Wikipedia, Sophomore's dream.

Formula

a(n) ~ A083648 * A002109(n).

a(0) = 0, a(n) = n^n * a(n-1) + (-1)^(n-1) * A002109(n-1).

Prog

(PARI) sum(k=1, n, (-1)^(k-1)/k^k) * prod(k=1, n, k^k)

Crossrefs

Cf. A083648.

Sequence in context: A120264 A292830 A185142 * A302947 A326948 A159053

Adjacent sequences: A279017 A279018 A279019 * A279021 A279022 A279023

Keyword

nonn,easy

Author

Daniel Suteu, Dec 03 2016

Status

approved