A007806 Integer part of Sum_{i=1..n} binomial(n,i) * (n/i)^i.

1, 5, 16, 50, 147, 422, 1210, 3459, 9878, 28189, 80425, 229411, 654311, 1866003, 5321194, 15173321, 43264523, 123357771, 351712022, 1002758190, 2858875748, 8150529454, 23236408366, 66243882238, 188849982251, 538372895393, 1534776215805, 4375251800924

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Maple

a:= n-> floor(add(binomial(n, i)*(n/i)^i, i = 1..n)):
seq(a(n), n=1..30);

Mathematica

Floor/@Table[Sum[Binomial[n, i](n/i)^i, {i, n}], {n, 30}] (* Harvey P. Dale, May 08 2012 *)

Prog

(PARI) a(n) = sum(i=1, n, binomial(n, i)*(n/i)^i)\1; \\ Michel Marcus, Oct 30 2018
(Sage) [floor( sum(binomial(n, j)*(n/j)^j for j in (1..n)) ) for n in (1..30)] # G. C. Greubel, Mar 06 2020

Crossrefs

Sequence in context: A192904 A082001 A084356 * A037480 A027108 A304168

Adjacent sequences: A007803 A007804 A007805 * A007807 A007808 A007809

Keyword

nonn

Author

Joseph Lavinus Ganley [ ganley(AT)virginia.edu ]

Extensions

Name corrected June 1995

Status

approved