A058871 Sum of next n primes (A007468) is prime for odd n or half the sum is prime for even n.

1, 3, 5, 7, 9, 13, 18, 20, 23, 25, 29, 48, 55, 98, 117, 119, 123, 130, 173, 187, 193, 198, 205, 213, 218, 223, 248, 249, 255, 259, 265, 268, 285, 292, 299, 311, 329, 346, 351, 386, 390, 393, 397, 411, 412, 448, 483, 487, 513, 515, 525, 554, 563, 574, 587, 597

Offset: 1

Author

Robert G. Wilson v, Jan 06 2001

Keywords

• nonn

Crossrefs

Cf. A007468.

Programs

Mathematica

Do[ s = Sum[ Prime[i], {i, n(n-1)/2 + 1, n(n+1)/2} ]; If[ PrimeQ[s] || PrimeQ[s/2], Print[n] ], {n, 10^3} ]