A118140 Index of A005846(n) in the primes.

13, 14, 15, 16, 18, 20, 23, 25, 30, 32, 36, 40, 45, 48, 54, 60, 65, 69, 76, 82, 89, 96, 101, 108, 116, 125, 132, 139, 147, 156, 164, 174, 184, 192, 202, 212, 220, 229, 241, 252, 283, 295, 318, 328, 342, 356, 377, 392, 407, 420, 432, 445, 472, 485, 501, 517, 531

Offset: 1

Author

Roger L. Bagula, May 11 2006

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000720, A005846.

Programs

Mathematica

a = Table[PrimePi[n^2 + n + 41], {n, 0, 39}] (* correct only up to 39 *)
PrimePi[Select[Table[n^2 + n + 41, {n, 0, 100}], PrimeQ]] (* Amiram Eldar, Sep 06 2024 *)

Formula

a(n) = PrimePi(A005846(n)) = A000720(A005846(n)).

Extensions

Offset corrected by Assoc. Eds. of the OEIS, Jun 15 2010