login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A037578
Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 1,3.
1
1, 9, 55, 333, 1999, 11997, 71983, 431901, 2591407, 15548445, 93290671, 559744029, 3358464175, 20150785053, 120904710319, 725428261917, 4352569571503, 26115417429021, 156692504574127, 940155027444765, 5640930164668591
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]
a(n)= 6*a(n-1) +a(n-2) -6*a(n-3). a(n) = 9*6^n/35 - 2/5 + (-1)^n/7. [R. J. Mathar, Oct 05 2009]
G.f.: x*(3*x+1) / ((x-1)*(x+1)*(6*x-1)). [Colin Barker, Dec 27 2012]
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
Sequence in context: A356339 A362365 A183805 * A096191 A362088 A281454
KEYWORD
nonn,base,easy
STATUS
approved