A070301 Numbers n such that sum of first 2n primes is prime.

1, 2, 3, 6, 7, 30, 32, 48, 50, 51, 54, 57, 61, 62, 65, 66, 73, 76, 79, 81, 89, 96, 99, 102, 103, 104, 107, 108, 148, 154, 163, 164, 165, 166, 167, 171, 175, 178, 179, 213, 223, 229, 230, 232, 240, 242, 244, 256, 265, 268, 274, 284, 310, 315, 338, 340, 348, 354

Offset

1,2

Comments

6 is in the sequence because the sum of the first 2*6=12 primes as 2+3+5+7+11+13+17+19+23+29+31+37=197 which is prime.

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Mathematica

p = 0; Do[p = p + Prime[2n - 1] + Prime[2n]; If[ PrimeQ[p], Print[n]], {n, 1, 10^4}]
nn=360; With[{prs=Prime[Range[2nn]]}, Select[Range[nn], PrimeQ[Total[Take[ prs, 2#]]]&]] (* Harvey P. Dale, Aug 22 2011 *)

Prog

(PARI) list(lim)=my(v=List(), n, s); lim\=1; lim*=2; forprime(p=2, , if(n++>lim, break); s+=p; if(n%2==0 && isprime(s), listput(v, n/2))); Vec(v) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A064731 A159069 A162681 * A329294 A291659 A302090

Adjacent sequences: A070298 A070299 A070300 * A070302 A070303 A070304

Keyword

nonn

Author

Lekraj Beedassy, May 10 2002

Extensions

Edited by Robert G. Wilson v, May 13 2002

Status

approved