1,3

May be the same sequence obtained from reading the terms of A002780 having only digits 0,1 in base 2 and converting to decimal.

Table of n, a(n) for n=1..26.

A069748(10)=10101 is the eighth number of A069748 having only digits 0 and 1. The binary number 10101 equals 21 in decimal. Thus a(8)=21.

Cf. A002780.

Sequence in context: A064411 A146556 A084229 * A144753 A220221 A212292

Adjacent sequences: A191353 A191354 A191355 * A191357 A191358 A191359

nonn,base

Vladimir Shevelev, May 31 2011

approved