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A037578
Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 1,3.
7
1, 9, 55, 333, 1999, 11997, 71983, 431901, 2591407, 15548445, 93290671, 559744029, 3358464175, 20150785053, 120904710319, 725428261917, 4352569571503, 26115417429021, 156692504574127, 940155027444765, 5640930164668591, 33845580988011549, 203073485928069295
OFFSET
1,2
FORMULA
a(n) = 5*a(n-1) + 6*a(n-2) + 4, a(0)=0, a(1)=1. - Zerinvary Lajos, Dec 14 2008
From R. J. Mathar, Oct 05 2009: (Start)
a(n) = 6*a(n-1) + a(n-2) - 6*a(n-3).
a(n) = 9*6^n/35 - 2/5 + (-1)^n/7. (End)
G.f.: x*(3*x+1)/((x-1)*(x+1)*(6*x-1)). - Colin Barker, Dec 27 2012
E.g.f.: exp(-x)*(5 - 14*exp(2*x) + 9*exp(7*x))/35. - Elmo R. Oliveira, Dec 27 2025
MAPLE
a[0]:=0:a[1]:=1:for n from 2 to 50 do a[n]:=5*a[n-1]+6*a[n-2]+4 od: seq(a[n], n=1..33); # Zerinvary Lajos, Dec 14 2008
MATHEMATICA
CoefficientList[Series[(3 x + 1)/((x - 1) (x + 1) (6 x - 1)), {x, 0, 30}], x] (* Vincenzo Librandi, Oct 21 2013 *)
PROG
(Magma) [9*6^n/35-2/5+(-1)^n/7: n in [1..30]]; // Vincenzo Librandi, Oct 21 2013
CROSSREFS
KEYWORD
nonn,base,easy
STATUS
approved