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 A052956 a(n) = 2^n + F_{n+1}. 0
 2, 3, 6, 11, 21, 40, 77, 149, 290, 567, 1113, 2192, 4329, 8569, 16994, 33755, 67133, 133656, 266325, 531053, 1059522, 2114863, 4222961, 8434976, 16852241, 33675825, 67305282, 134535539, 268949685, 537702952, 1075088093, 2149661957 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 1027 FORMULA G.f.: -(-2+3*x+x^2)/(-1+x+x^2)/(-1+2*x) Recurrence: {a(2)=6, a(1)=3, a(0)=2, 2*a(n)+a(n+1)-3*a(n+2)+a(n+3)} 2^n+Sum(1/5*(1+2*_alpha)*_alpha^(-1-n), _alpha=RootOf(-1+_Z+_Z^2)) MAPLE spec := [S, {S=Union(Sequence(Union(Prod(Z, Z), Z)), Sequence(Union(Z, Z)))}, unlabeled ]: seq(combstruct[count ](spec, size=n), n=0..20); CROSSREFS Cf. A000045, A000079. Sequence in context: A109222 A191789 A006861 * A298118 A008930 A164362 Adjacent sequences:  A052953 A052954 A052955 * A052957 A052958 A052959 KEYWORD easy,nonn AUTHOR encyclopedia(AT)pommard.inria.fr, Jan 25 2000 EXTENSIONS More terms from James A. Sellers, Jun 05 2000 STATUS approved

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Last modified March 18 22:11 EDT 2019. Contains 321305 sequences. (Running on oeis4.)