A121248 Numbers k such that the sum of the first 2^k primes is a prime.

0, 1, 2, 6, 9, 10, 32, 36, 55

Offset

1,3

Comments

Corresponding primes in the sums of the first 2^n primes or primes in A099825[n] are given in A113617[n] = {2,5,17,8893,868151,3875933,219554912086470964379,...}.

Links

Table of n, a(n) for n=1..9.

Formula

A099825(a(n)) = A113617(n). - Amiram Eldar, Jul 01 2024

Mathematica

Do[f=Sum[Prime[k], {k, 1, 2^n}]; If[PrimeQ[f], Print[{n, f}]], {n, 0, 32}]

Crossrefs

Cf. A099825, A013916, A013918, A113617.

Sequence in context: A370802 A370810 A071814 * A066586 A146974 A133160

Adjacent sequences: A121245 A121246 A121247 * A121249 A121250 A121251

Keyword

nonn,hard,more

Author

Alexander Adamchuk, Aug 22 2006

Extensions

Edited by Robert G. Wilson v, Aug 26 2006

a(7)-a(9) from Amiram Eldar, Jul 01 2024

Status

approved