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1,2
Let S(n) = sum_{k=1..n} a(k) be the partial sums. Then S(n) ~ c*A000217(n) for large n where c is a constant near 0.435.
Pierre CAMI, Table of n, a(n) for n = 1...8000
2*2*(2*2-1)-1=11 prime so k(1)=1 as 2=p(1) 2*2^2*(2*2^2-1)-1=55 composite 3*2^2*(3*2^2-1)=131 prime so k(2)=2 as 3=p(2)
Sequence in context: A006843 A049456 A117506 * A055089 A060117 A196526
Adjacent sequences: A179202 A179203 A179204 * A179206 A179207 A179208
nonn
Pierre CAMI, Jul 02 2010
approved