

A131505


n, 1, n, 2n+2.


0



0, 1, 0, 2, 1, 1, 1, 4, 2, 1, 2, 6, 3, 1, 3, 8, 4, 1, 4, 10, 5, 1, 5, 12, 6, 1, 6, 14, 7, 1, 7, 16, 8, 1, 8, 18, 9, 1, 9, 20, 10, 1, 10, 22, 11, 1, 11, 24, 12, 1, 12, 26, 13, 1, 13, 28, 14, 1, 14, 30, 15, 1, 15, 32, 16, 1, 16, 34, 17, 1, 17, 36, 18, 1, 18, 38, 19, 1, 19, 40, 20, 1, 20, 42, 21, 1, 21, 44, 22, 1, 22, 46, 23
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OFFSET

0,4


COMMENTS

Based on A129819 (the first with 0 0).


LINKS



FORMULA

G.f.: (x*(1  2*x + x^2  x^3))/(1  x + x^2  x^3)^2.  Georg Fischer, May 05 2021


MAPLE

seq(coeff(series( (x*(1  2*x + x^2  x^3))/(1  x + x^2  x^3)^2, x, n+1), x, n), n = 0..40); # Georg Fischer, May 05 2021


MATHEMATICA

Flatten[Table[{n, 1, n, 2n+2}, {n, 0, 30}]] (* Harvey P. Dale, Nov 15 2011 *)


CROSSREFS



KEYWORD

sign,easy


AUTHOR



STATUS

approved



