A192306 1-sequence of reduction of (2n) by x^2 -> x+1.
0, 4, 10, 26, 56, 116, 228, 436, 814, 1494, 2704, 4840, 8584, 15108, 26418, 45938, 79496, 136988, 235180, 402420, 686550, 1168174, 1982880, 3358416, 5676816, 9578116, 16133338, 27132746, 45565784, 76419524, 128006004, 214167220, 357935614
Offset: 1
Programs
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Mathematica
(* See A192305. *)
Formula
a(n) = 2*A122491(n+1).
G.f.: 2*x^2*(2-x)/((1-x)*(1-x-x^2)^2). - Colin Barker, Feb 11 2012
Comments