A010737 a(n) = 2*a(n-2) + 1.

4, 6, 9, 13, 19, 27, 39, 55, 79, 111, 159, 223, 319, 447, 639, 895, 1279, 1791, 2559, 3583, 5119, 7167, 10239, 14335, 20479, 28671, 40959, 57343, 81919, 114687, 163839, 229375, 327679, 458751, 655359

Offset

0,1

Links

Table of n, a(n) for n=0..34.

Formula

a(2n)=5*2^n-1 and a(2n+1)=7*2^n-1 or a(n)=(6-(-1)^n)*2^floor(n/2)-1 - Benoit Cloitre, May 04 2003

Maple

A010737 := proc(n) options remember; if n <= 1 then 2*n+4 else 2*A010737(n-2)+1; fi end;

Prog

(PARI) a(n)=(6-(-1)^n)*2^floor(n/2)-1

Crossrefs

Sequence in context: A187910 A283623 A020747 * A048625 A120134 A241451

Adjacent sequences: A010734 A010735 A010736 * A010738 A010739 A010740

Keyword

nonn,easy

Author

N. J. A. Sloane, Ulrich Hund (hund(AT)math.tu-berlin.de)

Status

approved