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A098971 a(0)=1; for n > 0, a(n)=a(floor(n/2))+2*a(floor(n/4)). 0
1, 3, 5, 5, 11, 11, 11, 11, 21, 21, 21, 21, 21, 21, 21, 21, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 43, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 85, 171, 171, 171, 171, 171 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

FORMULA

n>0, a(n)=(1/3)*(8*2^(floor(log(n)/log(2)))+(-1)^(floor(log(n)/log(2))))

PROG

(PARI) a(n)=if(n<1, 1, (1/3)*(8*2^(floor(log(n)/log(2)))+(-1)^(floor(log(n)/log(2)))))

CROSSREFS

a(2^n) gives the Jacobsthal sequence A001045(n+3).

Cf. A001045, A007731.

Sequence in context: A190864 A155537 A164663 * A093572 A118132 A089167

Adjacent sequences:  A098968 A098969 A098970 * A098972 A098973 A098974

KEYWORD

nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Oct 23 2004

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Last modified February 14 02:58 EST 2012. Contains 205567 sequences.