OFFSET
1,2
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..50 (terms < 10^11)
PROG
(PARI) {usigma(n, s=1, fac, i)= fac=factor(n); for(i=1, matsize(fac)[1], s=s*(1+fac[i, 1]^fac[i, 2]); ); return(s); } for(n=1, 10^6, if(issquare(usigma(n^3)), print1(n, " ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Jason Earls, Oct 05 2001
EXTENSIONS
More terms from Naohiro Nomoto, Oct 22 2001
a(8)-a(27) from Donovan Johnson, Jul 15 2012
STATUS
approved