A039593 - OEIS

A039593

Number of unitary divisors of central binomial coefficients.

1, 2, 2, 4, 4, 4, 4, 8, 8, 8, 16, 16, 16, 16, 16, 32, 32, 32, 32, 32, 64, 64, 64, 64, 64, 64, 64, 64, 128, 128, 128, 256, 256, 256, 512, 512, 512, 512, 1024, 1024, 1024, 1024, 1024, 1024, 512, 512, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 1024, 4096, 4096

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OFFSET

1,2

COMMENTS

As in A034444, all terms are powers of 2.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A034444(A001405(n)) = 2^A034973(n).

EXAMPLE

At n=5, the central binomial coefficient is 10, having 4 divisors, each of which is unitary, so a(5)=4.

MATHEMATICA