%I
%S 0,1,0,14,105,699,5012,40284,362835,3628745,39916734,479001522,
%T 6227020709,87178291095,1307674367880,20922789887864,355687428095847,
%U 6402373705727829,121645100408831810,2432902008176639790
%N Difference between the product of numbers up to n and the sum of numbers up to n.
%F a(n) = n! n*(n+1)/2
%t Table[n!  n(n + 1)/2, {n, 0, 20}]
%K easy,sign
%O 1,4
%A Emrehan Halici (emrehan(AT)halici.com.tr), Oct 31 2002
%E Edited by _Robert G. Wilson v_, Oct 31 2002
