OFFSET
1,2
EXAMPLE
For n = 4, with b(n) = A007955(n), a(4) = b(1)+b(2)+b(3)+b(4) = 1+2+3+8 = 14.
PROG
(PARI) prd(n) = my(dn = divisors(n)); prod(i=1, #dn, dn[i]);
a(n) = sum(k=1, n, prd(k)); \\ Michel Marcus, Dec 09 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 01 2010
EXTENSIONS
Edited and more terms from Michel Marcus, Dec 09 2014
STATUS
approved