OFFSET
1,3
COMMENTS
The number of terms of A056652 U {1} that divide n.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
MATHEMATICA
q[n_] := AllTrue[FactorInteger[n][[;; , 1]], # + 1 == 2^IntegerExponent[# + 1, 2] &]; f[p_, e_] := If[q[p], e + 1, 1]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100]
PROG
(PARI) a(n) = {my(f=factor(n)); prod(i=1, #f~, if((f[i, 1]+1) >> valuation(f[i, 1]+1, 2) == 1 , f[i, 2] + 1, 1))};
CROSSREFS
KEYWORD
nonn,easy,mult
AUTHOR
Amiram Eldar, Dec 29 2023
STATUS
approved