A125707 Numbers k such that A024528(k) is prime.

1, 2, 3, 4, 5, 7, 14, 15, 17, 23, 32, 36, 42, 309, 1384, 1588, 5631, 11226

Offset: 1

Author

Alexander Adamchuk, Feb 01 2007

Keywords

• nonn
• hard
• more

Crossrefs

Cf. A024528, A109628.

Programs

Mathematica

f=1;Do[p=Prime[n];f=f+1/p;g=Numerator[f];If[PrimeQ[g],Print[{n,p,g}]],{n,1,50}]

Extensions

a(14)-a(16) from Ryan Propper, Feb 11 2008

a(17)-a(18) from Michael S. Branicky, Apr 27 2025