A108230 a(1) = 0, a(n) = order of prime A088387(n).

0, 1, 2, 1, 3, 2, 4, 1, 2, 3, 5, 1, 6, 4, 3, 1, 7, 2, 8, 3, 4, 5, 9, 1, 3, 6, 2, 4, 10, 3, 11, 1, 5, 7, 4, 2, 12, 8, 6, 1, 13, 4, 14, 5, 2, 9, 15, 1, 4, 3, 7, 6, 16, 2, 5, 1, 8, 10, 17, 3, 18, 11, 2, 1, 6, 5, 19, 7, 9, 4, 20, 2, 21, 12, 3, 8, 5, 6, 22

Offset: 1

Author

Leroy Quet, Jun 16 2005

Keywords

• nonn

Examples

			a(12) = 1 because 2^2 is the largest prime power (yet not the power of the largest prime) dividing 12 and 2 is the first prime.
		

Crossrefs

Cf. A088387, A034699.

Programs

Mathematica

a = {0}; For[n = 2, n < 80, n++, max = 0; b = FactorInteger[n]; For[j = 1, j < Length[b] + 1, j++, If[b[[j, 1]]^b[[j, 2]] > max, max = b[[j, 1]]^b[[j, 2]]]]; AppendTo[a, PrimePi[FactorInteger[max][[1, 1]]]]]; a (* Stefan Steinerberger, Oct 24 2007 *)

Extensions

More terms from Stefan Steinerberger, Oct 24 2007