A092668 Bisection of A000011.

1, 2, 4, 9, 23, 63, 190, 612, 2056, 7155, 25482, 92205, 337594, 1246863, 4636390, 17334801, 65108062, 245492244, 928772650, 3524337980, 13409202676, 51141124287, 195470831356, 748607855769, 2872202028517, 11038251159312

Offset

0,2

Links

Table of n, a(n) for n=0..25.

Maple

with(numtheory): b:= proc(n) local s, d; if n = 0 then RETURN(1) else s := 2^(floor(n/2)); for d in divisors(n) do s := s+(phi(2*d)*2^(n/d))/(2*n); od; RETURN(s/2); fi; end: seq(b(2*n-1), n=1..30); # Emeric Deutsch, Feb 13 2006

Crossrefs

Cf. A000011, A000117.

Sequence in context: A001573 A135307 A000083 * A164039 A362549 A014137

Adjacent sequences: A092665 A092666 A092667 * A092669 A092670 A092671

Keyword

nonn,easy

Author

N. J. A. Sloane, Nov 24 2004

Extensions

More terms from Emeric Deutsch, Feb 13 2006

Status

approved