A144494 a(n) = 0 if n is prime, otherwise A001222(n).

0, 0, 0, 2, 0, 2, 0, 3, 2, 2, 0, 3, 0, 2, 2, 4, 0, 3, 0, 3, 2, 2, 0, 4, 2, 2, 3, 3, 0, 3, 0, 5, 2, 2, 2, 4, 0, 2, 2, 4, 0, 3, 0, 3, 3, 2, 0, 5, 2, 3, 2, 3, 0, 4, 2, 4, 2, 2, 0, 4, 0, 2, 3, 6, 2, 3, 0, 3, 2, 3, 0, 5, 0, 2, 3, 3, 2, 3, 0, 5, 4, 2, 0, 4, 2, 2, 2, 4, 0, 4, 2, 3, 2, 2, 2, 6, 0, 3, 3, 4, 0, 3, 0, 4, 3

Offset: 1

Author

N. J. A. Sloane, Dec 12 2008

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A001221, A001222, A087624, A055636.

Programs

Maple

with(numtheory); f:=n->if isprime(n) then 0 else bigomega(n); fi;

Mathematica

Table[If[PrimeQ[n], 0, PrimeOmega[n]], {n,1,100}] (* G. C. Greubel, Apr 25 2017 *)