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A267187
Column 4 of the square array in A267181.
1
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
0,2
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)
CROSSREFS
Cf. A267181.
Sequence in context: A130540 A076816 A021765 * A274716 A245434 A305100
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 17 2016
STATUS
approved