OFFSET
1,3
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..500
EXAMPLE
a(5) = gcd(1!,5!)+gcd(2!,3*4*5)+gcd(3!,4*5)+gcd(4!,5)=1+2+2+1 = 6.
PROG
(PARI) a(n) = sum(k=1, n-1, gcd(k!, n!/k!)); \\ Michel Marcus, Aug 04 2013
(Haskell)
a014454 n = sum $ zipWith gcd kfs $ map (div nf) kfs
where (nf:kfs) = reverse $ a166350_row n
-- Reinhard Zumkeller, Nov 11 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Feb 12 2002
STATUS
approved