OFFSET
1,2
COMMENTS
Also, the number of infinitary divisors of the smallest multiple of n whose number of divisors is a power of 2.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
MATHEMATICA
f[p_, e_] := 2^Ceiling[Log2[e + 1]]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100]
PROG
(PARI) s(n) = {my(e=logint(n + 1, 2)); if(n + 1 == 2^e, n + 1, 2^(e+1))};
a(n) = {my(f=factor(n)); prod(i=1, #f~, s(f[i, 2]))};
CROSSREFS
KEYWORD
nonn,easy,mult
AUTHOR
Amiram Eldar, Apr 28 2024
STATUS
approved