A153044 -id:A153044 - cp's OEIS frontend

A153041 Numbers n >=10 such that 2*n-19 is not a prime.

10, 14, 17, 20, 22, 23, 26, 27, 29, 32, 34, 35, 37, 38, 41, 42, 44, 47, 48, 50, 52, 53, 55, 56, 57, 59, 62, 65, 67, 68, 69, 70, 71, 72, 74, 76, 77, 80, 81, 82, 83, 86, 87, 89, 90, 92, 94, 95, 97, 98, 101, 102, 103, 104

Offset: 1

Vincenzo Librandi, Dec 17 2008

One more than associated values in A153051, two more than A153047. - R. J. Mathar, Jan 05 2011

The terms after a(1) are the values of 2*h*k + k + h + 10, where h and k are positive integers.- Vincenzo Librandi, Jan 19 2013

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

Cf. A097932, A155704.
Numbers n such that 2n-k is not prime: A104275 (k=1), A153043 (k=3), A153040 (k=5), A153039 (k=7), A153044 (k=9), A153045 (k=11), A153049 (k=13), A153047 (k=15), A153051 (k=17), A153041 (k=19).
Similar sequence listed also in A089559, A153144.

[n: n in [10..150] | not IsPrime(2*n - 19)]; // Vincenzo Librandi, Jan 19 2013

Select[Range[10, 200], !PrimeQ[2 # - 19] &] (* Vincenzo Librandi, Jan 19 2013 *)

Edited by N. J. A. Sloane, Jun 22 2010

A154631 Triangle read by rows: T(m,n) = 2mn + m + n + 5.

Original entry on oeis.org

9, 12, 17, 15, 22, 29, 18, 27, 36, 45, 21, 32, 43, 54, 65, 24, 37, 50, 63, 76, 89, 27, 42, 57, 72, 87, 102, 117, 30, 47, 64, 81, 98, 115, 132, 149, 33, 52, 71, 90, 109, 128, 147, 166, 185, 36, 57, 78, 99, 120, 141, 162, 183, 204, 225, 39, 62, 85, 108, 131, 154

Offset: 1

Vincenzo Librandi, Jan 17 2009

All terms are in A153044. - Vincenzo Librandi, Aug 30 2012

			Triangle begins:
9;
12, 17;
15, 22, 29;
18, 27, 36, 45;
21, 32, 43, 54, 65;
24, 37, 50, 63, 76, 89;
27, 42, 57, 72, 87, 102, 117;
30, 47, 64, 81, 98, 115, 132, 149;
33, 52, 71, 90, 109, 128, 147, 166, 185;
36, 57, 78, 99, 120, 141, 162, 183, 204, 225;

Vincenzo Librandi, Table of n, a(n) for Rows n = 1..100, flattened

Cf. A097069, A153044.

/* Triangle: */ [[2*m*n+m+n+5: m in [1..n]]: n in [1..10]]; // Bruno Berselli, Aug 31 2012

Flatten[Table[2 n m + m + n + 5, {n, 10}, {m, n}]] (* Vincenzo Librandi, Aug 30 2012 *)

Minor edits by Jon E. Schoenfield, Jun 23 2010

cp's OEIS Frontend

A153041 Numbers n >=10 such that 2*n-19 is not a prime.

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