A062810 a(n) = Sum_{i=1..n} i^(n - i) + (n - i)^i.

1, 3, 7, 17, 45, 131, 419, 1465, 5561, 22755, 99727, 465537, 2303829, 12037571, 66174411, 381560425, 2301307841, 14483421859, 94909491607, 646309392369, 4565559980989, 33401808977411, 252713264780595, 1974606909857945

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..600

Formula

a(n) = 2 * A026898(n-1) - 1.

a(n) = 2 * A003101(n-1) + 1.

Mathematica

Sum[i^(n - i) + (n - i)^i, {i, 1, n}]

Prog

(PARI) a(n) = sum(i=1, n, i^(n-i) + (n-i)^i); \\ Michel Marcus, Mar 24 2019

Crossrefs

Cf. A003101, A026898, A062811, A062812.

Sequence in context: A211281 A233656 A106191 * A113985 A309302 A320774

Adjacent sequences: A062807 A062808 A062809 * A062811 A062812 A062813

Keyword

nonn,easy

Author

Olivier Gérard, Jun 23 2001

Status

approved