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A154917 Zero followed by the Jacobsthal sequence A001045. 2
0, 0, 1, 1, 3, 5, 11, 21, 43, 85, 171, 341, 683, 1365, 2731, 5461, 10923, 21845, 43691, 87381, 174763, 349525, 699051, 1398101, 2796203, 5592405, 11184811, 22369621, 44739243, 89478485, 178956971, 357913941, 715827883, 1431655765, 2863311531 (list; graph; refs; listen; history; internal format)
OFFSET

0,5

FORMULA

a(n) = A001045(n-1), n>0.

a(n)+a(n+1) = A131577(n).

G.f.: x^2/((1+x)*(1-2*x)).

a(n)=(1/3)*[2^(n-1)-(-1)^(n-1)]-(1/2)*[C(2*n,n) mod 2], with n>=0 [From Paolo P. Lava (paoloplava(AT)gmail.com), Jan 19 2009]

CROSSREFS

Sequence in context: A152046 A001045 * A167167 A077925 A084230 A077465

Adjacent sequences:  A154914 A154915 A154916 * A154918 A154919 A154920

KEYWORD

nonn,easy,less

AUTHOR

Paul Curtz (bpcrtz(AT)free.fr), Jan 17 2009

EXTENSIONS

Notation cleaned up by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 07 2009

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Last modified February 16 12:15 EST 2012. Contains 205909 sequences.