A153083 Numbers such that 2*n + 11 is not prime.

2, 5, 7, 8, 11, 12, 14, 17, 19, 20, 22, 23, 26, 27, 29, 32, 33, 35, 37, 38, 40, 41, 42, 44, 47, 50, 52, 53, 54, 55, 56, 57, 59, 61, 62, 65, 66, 67, 68, 71, 72, 74, 75, 77, 79, 80, 82, 83, 86, 87, 88, 89, 92, 95, 96, 97, 98, 99, 101, 102, 103, 104, 105, 107, 110, 112

Offset: 1

Author

Vincenzo Librandi, Dec 18 2008

Keywords

• nonn
• easy

Comments

One less than the associated entry in A155723. [ R. J. Mathar, Jan 05 2011]

Examples

			Distribution of the terms in the following triangular array:
*
2,7;
5,12,19;
8,17,26,35;
11,22,33,44,55;
14,27,40,53,66,79;
17,32,47,62,77,92,107;
20,37,54,71,88,105,122,139;
23,42,61,80,99,118,137,156,175;
26,47,68,89,110,131,152,173,194,215;
29,52,75,98,121,144,167,190,213,236,259;
32,57,82,107,132,157,182,207,232,257,282,307;
where * marks the decimal values of (2*h*k + k + h - 5) with h >= k >= 1. - _Vincenzo Librandi_, Jan 16 2013
		

Links

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

Crossrefs

Cf. A101448, A155546, A155723, A153053.

Programs

Magma

[n: n in [1..120] | not IsPrime(2*n + 11)]; // Vincenzo Librandi, Nov 21 2012

Mathematica

Select[Range[100],!PrimeQ[2#+11]&] (* Harvey P. Dale, Jul 18 2011 *)