0,2

The only n such that a(n) = n are 0 and 18.

Table of n, a(n) for n=0..76.

Erich Friedman, What's Special About This Number?

a(n) = 2*A007953(n).

Cf. A007953.

Sequence in context: A136614 A245627 A097586 * A263042 A230099 A098727

Adjacent sequences: A169802 A169803 A169804 * A169806 A169807 A169808

nonn,base

N. J. A. Sloane, May 24 2010

approved