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A076684
Odd terms in A027941.
0
1, 33, 609, 10945, 196417, 3524577, 63245985, 1134903169, 20365011073, 365435296161, 6557470319841, 117669030460993, 2111485077978049, 37889062373143905, 679891637638612257, 12200160415121876737
OFFSET
0,2
FORMULA
a(n) = F(6n+3) - 1 where F(k) denotes the k-th Fibonacci number.
G.f.: (1+14x+x^2)/((1-x)(1-18x+x^2)).
MATHEMATICA
a[n_] := Fibonacci[6n+3]-1
PROG
(PARI) a(n)=fibonacci(6*n+3)-1
(PARI) a(n)=if(n<0, 0, subst(poltchebi(n)+poltchebi(n+1), x, 9)/5-1)
CROSSREFS
Sequence in context: A282926 A172362 A080597 * A181382 A252926 A225970
KEYWORD
nonn,easy
AUTHOR
Benoit Cloitre, Oct 25 2002
STATUS
approved