OFFSET
1,2
LINKS
FORMULA
If n is squarefree product of k distinct primes, then a(n) = 6^k.
If n = p^2, then a(n) = 15, etc.
MATHEMATICA
Table[LCM[DivisorSigma[0, n], DivisorSigma[0, n^2]], {n, 80}] (* Harvey P. Dale, Dec 26 2018 *)
PROG
(PARI) A072695(n) = lcm(numdiv(n), numdiv(n^2)); \\ Antti Karttunen, Nov 24 2017
(PARI) a(n) = {my(e = factor(n)[, 2]); lcm(vecprod(apply(x -> 2*x+1, e)), vecprod(apply(x -> x+1, e))); } \\ Amiram Eldar, Dec 02 2023
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Labos Elemer, Jul 04 2002
STATUS
approved