
1, 2, 1, 5, 2, 2, 1, 6, 11, 4, 2, 5, 5, 2, 2, 29, 4, 22, 3, 10, 1, 4, 2, 6, 29, 10, 3, 5, 6, 4, 1, 20, 2, 8, 2, 55, 17, 6, 5, 12, 10, 2, 7, 10, 22, 4, 2, 29, 34, 58, 4, 25, 8, 6, 4, 6, 3, 12, 6, 10, 29, 2, 11, 113, 10, 4, 13, 20, 2, 4, 4, 66, 31, 34, 29, 15, 2, 10, 3, 58, 49, 20, 10, 5, 8, 14, 6, 12, 12, 44, 5, 10
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OFFSET

1,2


LINKS



FORMULA

Multiplicative with a(p^e) = A064989(1 + p + p^2 + ... + p^e).


MATHEMATICA

f[2, e_] := 1; f[p_, e_] := NextPrime[p, 1]^e; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[DivisorSigma[1, n]]; Array[a, 100] (* Amiram Eldar, Dec 12 2021 *)


PROG

(PARI)
A064989(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = if(2==f[i, 1], 1, precprime(f[i, 1]1))); factorback(f); };


CROSSREFS



KEYWORD

nonn,mult


AUTHOR



STATUS

approved

