1,2

Table of n, a(n) for n=1..72.

To compute a(2), we see a(1) is 1; we look for the smallest unused positive integer that does not have the same prime signature as either 1 or 2. The first such number is 4.

Cf. A179372

Sequence in context: A206798 A200366 A217296 * A097455 A201520 A179022

Adjacent sequences: A179368 A179369 A179370 * A179372 A179373 A179374

nonn

Will Nicholes, Jul 11 2010

approved