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A372468
The number of divisors of the numbers whose number of divisors is a power of 2 (A036537).
3
1, 2, 2, 2, 4, 2, 4, 4, 2, 2, 4, 4, 2, 2, 4, 4, 2, 8, 4, 4, 2, 8, 2, 4, 4, 4, 2, 4, 4, 8, 2, 8, 2, 4, 2, 4, 2, 8, 4, 8, 4, 4, 2, 2, 4, 4, 8, 2, 4, 8, 2, 2, 4, 4, 8, 2, 4, 2, 4, 4, 4, 8, 2, 4, 4, 4, 4, 2, 2, 8, 2, 8, 8, 4, 2, 2, 8, 4, 2, 8, 4, 4, 4, 16, 4, 4, 4
OFFSET
1,2
COMMENTS
Also, the number of infinitary divisors of the numbers whose number of divisors is a power of 2.
LINKS
FORMULA
a(n) = A000005(A036537(n)).
a(n) = A037445(A036537(n)).
a(n) = A372470(A036537(n)).
a(n) = 2^A372469(n).
MATHEMATICA
Select[DivisorSigma[0, Range[300]], # == 2^IntegerExponent[#, 2] &]
PROG
(PARI) lista(n) = select(x -> x >> valuation(x, 2) == 1, vector(n, i, numdiv(i)));
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Amiram Eldar, May 02 2024
STATUS
approved