A138363 Number of prime powers p^e with e>1 and 0

0, 0, 1, 0, 1, 0, 1, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0

Offset: 1

Author

Reinhard Zumkeller, Mar 16 2008

Keywords

• nonn

Comments

a(A049084(A074267(n))) > 0;

a(31)=2, what is the next value greater than 1?.

Examples

			A000040(10)=29: a(10) = #{4+5^2, 2+3^3} = 2.
		

Links

• R. Zumkeller, Table of n, a(n) for n = 1..10000

Programs

Mathematica

 f[n_] := Block[{c = 0, j, k = 1, p = Prime@ n, q}, j = 1 + PrimePi@ Sqrt@ p; While[k < j, q = Prime@ k; If[p < q + q^Floor@ Log[q, p], c++ ]; k++ ]; c]; Array[f, 105]