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

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

Crossrefs

Cf. A063170, A090878, A093101, A120266, A214401.

Sequence in context: A247984 A108417 A185078 * A166064 A144675 A088417

Adjacent sequences: A214399 A214400 A214401 * A214403 A214404 A214405

Keyword

nonn

Author

Jonathan Sondow, Jul 15 2012

Extensions

More terms from Michel Marcus, Apr 20 2021

Status

approved