A228199 Smallest of 7 consecutive primes whose sum is not a prime.

2, 3, 5, 7, 11, 13, 37, 41, 59, 67, 73, 83, 101, 109, 131, 139, 149, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 239, 241, 251, 263, 269, 271, 277, 281, 283, 293, 307, 311, 331, 337, 347, 349, 353, 389, 397, 409, 419, 421, 431, 433, 439, 443

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Example

59 is in the sequence because 59+61+67+71+73+79+83 = 493 and 493 is not a prime.

Mathematica

Transpose[Select[Partition[Prime[Range[150]], 7, 1], ! PrimeQ[Total[#]] &]][[1]]
Prime[Select[Range[100], ! PrimeQ[Sum[Prime[# + i], {i, 0, 6}]] &]] (* Bruno Berselli, Aug 22 2013 *)

Prog

(Magma) [NthPrime(n): n in [1..120] |not IsPrime(&+[NthPrime(n+s): s in [0..6]])];

Crossrefs

Cf. A000040, A180948.

Sequence in context: A191077 A262377 A237600 * A128292 A140464 A037174

Adjacent sequences: A228196 A228197 A228198 * A228200 A228201 A228202

Keyword

nonn

Author

Vincenzo Librandi, Aug 20 2013

Status

approved