0,3

Table of n, a(n) for n=0..100.

a(n) = A002828(A000041(n)).

a(20) = 3 because P(20) = 627 = 25^2 + 1^2 + 1^2.

a(36) = 2 because P(36) = 17977 = 124^2 + 51^2, which is prime.

a(66) = 2 because P(66) = 2323520 = 1504^2 + 248^2.

a(67) = 2 because P(67) = 2679689 = 1205^2 + 1108^2.

a(100) = 3 because P(100) = 190569292 = 13730^2 + 1434^2 + 6^2.

Cf. A000009, A000041, A000203, A008284, A002828, A001318, A046063, A103266, A118487.

Sequence in context: A122060 A088939 A004596 * A173753 A295753 A144968

Adjacent sequences: A118650 A118651 A118652 * A118654 A118655 A118656

easy,nonn

Jonathan Vos Post, May 17 2006

approved