A214402 - OEIS

A214402

Cancellation factor in reducing Sum_{k=0...n} n^k/k! to lowest terms.

1, 2, 6, 8, 10, 144, 70, 128, 162, 6400, 22, 6220800, 26, 100352, 182250, 425984, 170, 429981696, 38, 163840000, 13502538, 317194240, 46, 247669456896, 31250, 1417674752, 15943230, 80564191232, 9802, 25076532510720000000, 62, 10737418240, 38196790434, 1241245548544

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

OFFSET

1,2

LINKS

Michel Marcus, Table of n, a(n) for n = 1..300

Eric Weisstein, Exponential Sum Function.

FORMULA

a(n) = n!/A214401(n).

MATHEMATICA

Table[n!/Denominator[Sum[n^k/k!, {k, 0, n}]], {n, 1, 30}]

PROG

(PARI) a(n) = n!/denominator(sum(k=0, n, n^k/k!)); \\ Michel Marcus, Apr 20 2021