

A153643


Jacobsthal numbers A001045 incremented by 2.


6



2, 3, 3, 5, 7, 13, 23, 45, 87, 173, 343, 685, 1367, 2733, 5463, 10925, 21847, 43693, 87383, 174765, 349527, 699053, 1398103, 2796205, 5592407, 11184813, 22369623, 44739245, 89478487, 178956973, 357913943, 715827885, 1431655767, 2863311533, 5726623063
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OFFSET

0,1


LINKS

G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2,1,2).


FORMULA

a(n) = 2 + A001045(n) = A001045(n) + A007395(n) = 1 + A128209(n).
a(n)  A010684(n) = A078008(n), first differences of A001045.  Paul Curtz, Jan 17 2009
G.f.: (2  x  5x^2)/((1+x)(1x)(12x)).  R. J. Mathar, Jan 23 2009
a(n) = 2*a(n1) + a(n2)  2*a(n3).  Andrew Howroyd, Feb 26 2018


MATHEMATICA

LinearRecurrence[{1, 2}, {0, 1}, 40]+2 (* Harvey P. Dale, May 26 2014 *)


CROSSREFS

Sequence in context: A258967 A290000 A035068 * A053218 A198335 A296335
Adjacent sequences: A153640 A153641 A153642 * A153644 A153645 A153646


KEYWORD

nonn,easy


AUTHOR

Paul Curtz, Dec 30 2008


EXTENSIONS

Edited and extended by R. J. Mathar, Jan 23 2009


STATUS

approved



