A267187 Column 4 of the square array in A267181.

0, 3, 1, 4, 0, 6, 4, 7, 2, 7, 5, 8, 3, 8, 6, 9, 4, 9, 7, 10, 5, 10, 8, 11, 6, 11, 9, 12, 7, 12, 10, 13, 8, 13, 11, 14, 9, 14, 12, 15, 10, 15, 13, 16, 11, 16, 14, 17, 12, 17, 15, 18, 13, 18, 16, 19, 14, 19, 17, 20, 15, 20, 18, 21, 16, 21, 19, 22, 17, 22, 20, 23

Offset: 0

Author

N. J. A. Sloane, Jan 17 2016

Keywords

• nonn

Crossrefs

Cf. A267181.

Formula

Conjectures from Colin Barker, Jan 29 2016: (Start)

a(n) = a(n-1)+a(n-4)-a(n-5) for n>5.

G.f.: x*(3-2*x+3*x^2-4*x^3+3*x^4-x^7-x^8) / ((1-x)^2*(1+x)*(1+x^2)).

(End)