OFFSET
1,2
COMMENTS
Not all a(n) are 1 mod 24. First counterexample is 5036684. But for a prime p, with sigma(p^4) squarefree and omega(sigma(p^4)==3, p^2 is in a(n). For these primes (as for all primes > 3), p^2 = 1 mod 24. - Lambert Herrgesell (lambert.herrgesell(AT)googlemail.com), Jan 08 2007, edited by Robert Israel, Oct 22 2018.
LINKS
Robert Israel, Table of n, a(n) for n = 1..200
MAPLE
filter:= proc(n) uses numtheory: sigma(tau(n^3))=tau(sigma(n^2)) end proc:
select(filter, [$1..10^6]); # Robert Israel, Oct 22 2018
PROG
(PARI) for(n=1, 10^7, if(sigma(numdiv(n^3))==numdiv(sigma(n^2)), print(n)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Jason Earls, Aug 19 2001
EXTENSIONS
More terms from Robert Israel, Oct 22 2018
STATUS
approved