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A022322
a(n) = a(n-1) + a(n-2) + 1, with a(0) = 1 and a(1) = 8.
1
1, 8, 10, 19, 30, 50, 81, 132, 214, 347, 562, 910, 1473, 2384, 3858, 6243, 10102, 16346, 26449, 42796, 69246, 112043, 181290, 293334, 474625, 767960, 1242586, 2010547, 3253134, 5263682, 8516817
OFFSET
0,2
FORMULA
From R. J. Mathar, Apr 07 2011: (Start)
G.f.: (1+6*x-6*x^2)/((1-x)*(1-x-x^2)).
a(n) = A022114(n) - 1. (End)
a(n) = 2*F(n+2) + 5*F(n) - 1, where F = A000045. - G. C. Greubel, Aug 25 2017
MATHEMATICA
LinearRecurrence[{2, 0, -1}, {1, 8, 10}, 40] (* Harvey P. Dale, Oct 14 2012 *)
PROG
(PARI) x='x+O('x^50); Vec((1+6*x-6*x^2)/((1-x)*(1-x-x^2))) \\ G. C. Greubel, Aug 25 2017
CROSSREFS
Sequence in context: A090097 A236653 A257274 * A302637 A230862 A281067
KEYWORD
nonn
STATUS
approved