1,2

Table of n, a(n) for n=1..16.

Repeat each nonzero term of A003422 once, then take partial sums.

a(5) = 10 = sum of row 5 terms of triangle A138015: (1 + 2 + 4 + 2 + 1).

a(5) = 10 = (1 + 1 + 2 + 2 + 4) since A003422 starting (1, 2, 4, 10, 34, 154,...)then repeating each term = (1, 1, 2, 2, 4, 4, 10, 10,...). Take partial sums of the first 5 terms.

Cf. A003422, A138015.

Sequence in context: A077625 A027383 A280611 * A239787 A113118 A287636

Adjacent sequences: A138013 A138014 A138015 * A138017 A138018 A138019

nonn

Gary W. Adamson, Feb 28 2008

approved