OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..1000
EXAMPLE
For n = 4, A007955(n) = b(n): a(4) = b(1)*b(4/1) + b(2)*b(4/2) + b(4)*b(4/4) = 1*8 + 2*2 + 8*1 = 20.
PROG
(PARI) a(n)={sumdiv(n, d, vecprod(divisors(d))*vecprod(divisors(n/d)))} \\ Andrew Howroyd, Jan 05 2020
(Magma) [&+[&*Divisors(d)*&*Divisors(n div d):d in Divisors(n)]:n in [1..50]]; // Marius A. Burtea, Jan 05 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Apr 02 2010
EXTENSIONS
Terms a(31) and beyond from Andrew Howroyd, Jan 05 2020
STATUS
approved