A144670 Triangle read by rows where T(m,n)=2mn+m+n-7.

-3, 0, 5, 3, 10, 17, 6, 15, 24, 33, 9, 20, 31, 42, 53, 12, 25, 38, 51, 64, 77, 15, 30, 45, 60, 75, 90, 105, 18, 35, 52, 69, 86, 103, 120, 137, 21, 40, 59, 78, 97, 116, 135, 154, 173, 24, 45, 66, 87, 108, 129, 150, 171, 192, 213, 27, 50, 73, 96, 119, 142, 165, 188, 211, 234, 257

Offset: 1

Author

Vincenzo Librandi, Jan 28 2009

Keywords

• tabl
• sign

Comments

Numbers n such that, if 2^(s-1)=n then [A144487] is not prime.

Let p (prime number), n=(p^2-15)/2 mod(p).

Examples

			Triangle begins:
-3;
0, 5;
3, 10, 17;
6, 15, 24, 33;
9, 20, 31, 42, 53;
12, 25, 38, 51, 64, 77;
15, 30, 45, 60, 75, 90, 105;
18, 35, 52, 69, 86, 103, 120, 137;
21, 40, 59, 78, 97, 116, 135, 154, 173;
24, 45, 66, 87, 108, 129, 150, 171, 192, 213;
= = = = = = = =
		

Links

• Vincenzo Librandi, Rows n = 100, flattened

Crossrefs

Cf. A057197, A144487.

Programs

Magma

[2*n*k + n + k -7: k in [1..n], n in [1..12]]; // Vincenzo Librandi, Oct 15 2012

Mathematica

t[n_,k_]:=2 n*k+n+k-7; Table[t[n, k], {n, 12}, {k, n}] // Flatten (* Vincenzo Librandi, Oct 15 2012 *)