A153350 Numbers n such that 7n+11 is not prime.

1, 2, 3, 4, 5, 7, 9, 10, 11, 12, 13, 15, 16, 17, 19, 21, 22, 23, 25, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 69, 70, 71, 72, 73, 74, 75, 76, 77, 79, 81, 82, 83, 85, 87, 88, 89

Offset

1,2

Links

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

Example

Distribution of the even terms in the following triangular array:
*;
*,2;
*,*,*;
*,*,*,10;
*,*,*,*,*;
4,*,*,*,*,*;
*,*,*,*,22,*,*;
*,*,*,*,*,30,*,*;
*,12,*,*,*,*,*,*,50;
*,*,*,*,*,*,*,*,*,*;
*,*,*,28,*,*,*,*,*,*,74;
*,*,*,*,*,*,52,*,*,*,*,*;
10,*,*,*,*,*,*,64,*,*,*,*,*; etc.
where * marks the non-integer values of (4*h*k + 2*k + 2*h - 10)/7 with h >= k >= 1. - Vincenzo Librandi, Jan 17 2013

Mathematica

Select[Range[200], !PrimeQ[7 # + 11] &] (* Vincenzo Librandi, Jan 13 2013 *)

Prog

(PARI) isA153350(n)=!isprime(7*n+11)
(Magma) [n: n in [0..150] | not IsPrime(7*n+11)]; // _VIncenzo Librandi_, Jan 13 2013

Crossrefs

Cf. A101123.

Sequence in context: A039201 A039151 A039110 * A191919 A039055 A047504

Adjacent sequences: A153347 A153348 A153349 * A153351 A153352 A153353

Keyword

nonn,easy

Author

Vincenzo Librandi, Dec 24 2008

Extensions

Corrected and edited by Michael B. Porter, Apr 20 2010

Status

approved