A007610 Sum of n consecutive primes starting at a(n) is prime (or 0 if impossible).

2, 2, 5, 2, 5, 2, 17, 0, 3, 0, 5, 2, 29, 2, 3, 0, 3, 0, 11, 0, 7, 0, 7, 0, 5, 0, 7, 0, 13, 0, 13, 0, 7, 0, 5, 0, 5, 0, 13, 0, 7, 0, 7, 0, 7, 0, 7, 0, 11, 0, 17, 0, 3, 0, 3, 0, 97, 0, 29, 2, 3, 0, 13, 2, 3, 0, 19, 0, 19, 0, 3, 0, 5, 0, 3, 0, 23, 0, 7, 0, 11, 0, 53, 0, 31, 0, 89, 0, 53, 0, 19, 0, 11, 0, 3, 2

Offset: 1

Author

N. J. A. Sloane, Robert G. Wilson v, Mira Bernstein

Keywords

• nonn
• nice
• easy

Comments

a(n) = 0 iff n is even and the sum of 2..P(n) is not prime. See A013916. - Robert G. Wilson v, Feb 16 2002

References

• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
• C. W. Trigg, Prime sums of consecutive primes, J. Rec. Math., 18 (No. 4, 1985-1986), 247-248.

Links

• T. D. Noe, Table of n, a(n) for n = 1..10000
• C. W. Trigg, Prime sums of consecutive primes, J. Rec. Math., 18 (No. 4, 1985-1986), 247-248. (Annotated scanned copy)

Crossrefs

Cf. A013916, A071149.

Programs

Mathematica

f[n_] := If[OddQ@ n, Block[{k = 1}, While[ !PrimeQ[Plus @@ Prime[Range[k, k + n - 1]]], k++]; Prime@ k], If[ PrimeQ[Plus @@ Prime@ Range@ n], 2, 0]]; Array[f, 96] (* Robert G. Wilson v, May 11 2015 *)