A076128 Difference between the product of numbers up to n and the sum of numbers up to n.

0, -1, 0, 14, 105, 699, 5012, 40284, 362835, 3628745, 39916734, 479001522, 6227020709, 87178291095, 1307674367880, 20922789887864, 355687428095847, 6402373705727829, 121645100408831810, 2432902008176639790

Offset

1,4

Links

Table of n, a(n) for n=1..20.

Formula

a(n) = n!- n*(n+1)/2

Mathematica

Table[n! - n(n + 1)/2, {n, 0, 20}]

Crossrefs

Sequence in context: A022579 A061179 A285752 * A206761 A190868 A125351

Adjacent sequences: A076125 A076126 A076127 * A076129 A076130 A076131

Keyword

easy,sign

Author

Emrehan Halici (emrehan(AT)halici.com.tr), Oct 31 2002

Extensions

Edited by Robert G. Wilson v, Oct 31 2002

Status

approved