A172036 Prime partial sums of safe primes A005385.

5, 23, 509, 2267, 9157, 26437, 44357, 55921, 82301, 184843, 276173, 611069, 732271, 757577, 1006559, 1067611, 1195547, 2132113, 2576683, 3243511, 3302393, 4258091, 5530033, 7326931, 7984121, 10518353, 10748449, 10864151, 11096587, 11937257

Offset

1,1

Comments

a(2) = 23 is not only the 3rd partial sum of safe primes, but is itself the 4th safe prime. What are the next safe prime partial sums of safe primes [no more through 66869(41)]?

Links

Table of n, a(n) for n=1..30.

Formula

A000040 INTERSECTION A066869 = A000040 INTERSECTION = SUM[i=1..n]A005385 (i) = {p such that p prime and (p-1)/2 prime and p is an element of SUM[i=1..n]{p prime and (p-1)/2 prime}.}.

Example

a(1) = 5 = A066869(1) is prime. a(2) = 23 = A066869(3) is prime. a(3) = 2267 = A066869(15) is prime.

Crossrefs

Cf. A005384, A005385, A066869.

Sequence in context: A023275 A018899 A080990 * A003487 A361402 A055490

Adjacent sequences: A172033 A172034 A172035 * A172037 A172038 A172039

Keyword

easy,nonn

Author

Jonathan Vos Post, Jan 23 2010

Extensions

Corrected and extended by Max Alekseyev, Apr 22 2010

Status

approved