A007829 From random walks on complete directed triangle.
0, 0, 0, 0, 0, 6, 8, 28, 44, 100, 162, 318, 514, 942, 1518, 2672, 4302, 7380, 11882, 20040, 32276, 53810, 86710, 143396, 231204, 380152, 613286, 1004188, 1620864, 2645928, 4272744, 6959326, 11242518, 18281222, 29542078, 47978666, 77552928, 125836374, 203445784
Offset: 0
Links
- Sean A. Irvine, Table of n, a(n) for n = 0..500
- E. Bussian, Email to N. J. A. Sloane, Oct. 1994
- Index entries for linear recurrences with constant coefficients, signature (2,3,-6,-4,5,5,-2,-2).
Programs
-
Maple
m:=35; S:=series(2*x^5*(3-2*x-3*x^2)/((1-x)*(1-x-x^2)*(1-2*x^2)*(1-x^2-x^3)), x, m+1): seq(coeff(S, x, j), j=0..m); # G. C. Greubel, Mar 11 2020
-
Mathematica
b[n_]:= b[n]= If[n==0, 1, If[n<3, 0, b[n-2] +b[n-3]]]; Table[2*(2 +Fibonacci[n+2] -2^Floor[n/2] -p[n+7] -p[n+5]), {n,0,35}] (* G. C. Greubel, Mar 11 2020 *)
-
Sage
def A007829_list(prec): P.
= PowerSeriesRing(ZZ, prec) return P( 2*x^5*(3-2*x-3*x^2)/((1-x)*(1-x-x^2)*(1-2*x^2)*(1-x^2-x^3)) ).list() A007829_list(35) # G. C. Greubel, Mar 11 2020
Formula
From Colin Barker, Feb 03 2018: (Start)
G.f.: 2*x^5*(3 - 2*x - 3*x^2) / ((1 - x)*(1 - x - x^2)*(1 - 2*x^2)*(1 - x^2 - x^3)).
a(n) = 2*a(n-1) + 3*a(n-2) - 6*a(n-3) - 4*a(n-4) + 5*a(n-5) + 5*a(n-6) - 2*a(n-7) - 2*a(n-8) for n>7.
(End)
From G. C. Greubel, Mar 11 2020: (Start)
a(n) = 2*(2 + Fibonacci(n+2) - 2^floor(n/2) - A084338(n+2)).
a(n) = 2*(2 + Fibonacci(n+2) - 2^floor(n/2) - b(n+7) - b(n+5)), where b(n) = A000931(n). (End)
Comments