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A099013 Sum_{ k=0..n} 3^(k-1)Fib(k). 1
0, 1, 4, 22, 103, 508, 2452, 11929, 57856, 280930, 1363495, 6618856, 32128024, 155953777, 757013548, 3674624638, 17836995847, 86582609284, 420280790476, 2040085854985, 9902784679240, 48069126732586, 233332442310919 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Partial sums of A099012. Binomial transform of A063092 (with leading 0).

LINKS

Index to sequences with linear recurrences with constant coefficients, signature (4,6,-9).

FORMULA

G.f.: x/((1-x)(1-3x-9x^2));

a(n)=4a(n-1)+6a(n-2)-9a(n-3);

a(n)=3^(n-1)*sum{k=0..n, Fib(n-k)3^(-k)};

a(n)=(3/2+3sqrt(5)/2)^n(1/22+7sqrt(5)/110)+(1/22-7sqrt(5)/110)(3/2-3sqrt(5)/2)^n-1/11.

MATHEMATICA

Join[{a=0, b=1}, Table[c=3*b+9*a+1; a=b; b=c, {n, 60}]] (*From Vladimir Joseph Stephan Orlovsky, Jan 18 2011*)

Table[Sum[3^(k-1) Fibonacci[k], {k, 0, n}], {n, 0, 30}] (* or *) LinearRecurrence[{4, 6, -9}, {0, 1, 4}, 30] (* From Harvey P. Dale, Dec 09 2011 *)

CROSSREFS

Cf. A000045.

Sequence in context: A007901 A088581 A017970 * A184510 A184701 A001436

Adjacent sequences:  A099010 A099011 A099012 * A099014 A099015 A099016

KEYWORD

easy,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Sep 22 2004

EXTENSIONS

Sign in second formula corrected by Harvey P. Dale, Dec 09 2011

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Last modified February 17 18:33 EST 2012. Contains 206073 sequences.