3,1

Conjecture: a(n) = 4 for all prime numbers >= 3 and 3 for all composites

Third column of triangle in A081532. - N. J. A. Sloane, Oct 12 2010.

Antti Karttunen, Table of n, a(n) for n = 3..2000 (computed from the b-file of A005179 provided by Don Reble)

a(n) = A292269(A005179(n)) for n >= 3. - Antti Karttunen, Oct 04 2017

a(4) = 3 because the divisors of 6 are 1, 2, 3, 6.

Cf. A081532, A171784. - N. J. A. Sloane, Oct 12 2010.

Cf. A005179, A292269.

Sequence in context: A108171 A231475 A106055 * A251767 A168309 A103947

Adjacent sequences: A171780 A171781 A171782 * A171784 A171785 A171786

nonn

J. Lowell, Oct 12 2010

More terms from R. J. Mathar, Oct 13 2010

approved