1,3

k is the number of divisors of arithmetic numbers A003601.

Table of n, a(n) for n=1..85.

a(12) = 5 because 1 + 2 + 4 + 6 + 12 = 25 = 5*5 for m = 5.

Cf. A000203, A003601, A049642.

Sequence in context: A027389 A111735 A211454 * A102298 A049298 A075016

Adjacent sequences: A242307 A242308 A242309 * A242311 A242312 A242313

nonn

Ilya Lopatin and Juri-Stepan Gerasimov, May 10 2014

approved