1,1
This sequence is the sequence of factorials starting from 24. (It can be easily checked that any number divisible by 12 is abundant.)
Table of n, a(n) for n=1..17.
G(x):=x^4/(1-x): f[0]:=G(x): for n from 1 to 20 do f[n]:=diff(f[n-1], x) od: x:=0: seq(f[n], n=4..20); # Zerinvary Lajos, Apr 03 2009
Cf. A000142 Factorial numbers. A005101 Abundant numbers.
Sequence in context: A235702 A052754 A050213 * A293050 A052581 A052605
Adjacent sequences: A124654 A124655 A124656 * A124658 A124659 A124660
nonn
Tanya Khovanova, Dec 27 2006
approved