A163657 Triangle T(m,n) = 2*m*n + m + n + 8 read by rows.

12, 15, 20, 18, 25, 32, 21, 30, 39, 48, 24, 35, 46, 57, 68, 27, 40, 53, 66, 79, 92, 30, 45, 60, 75, 90, 105, 120, 33, 50, 67, 84, 101, 118, 135, 152, 36, 55, 74, 93, 112, 131, 150, 169, 188, 39, 60, 81, 102, 123, 144, 165, 186, 207, 228, 42, 65, 88, 111, 134, 157, 180

Offset: 1

Author

Vincenzo Librandi, Aug 02 2009

Keywords

• nonn
• easy
• tabl

Comments

If p=2*n+1 is a prime number, then T(n,n) = (p^2+15)/2.

First column: 3*A020705; second column: 5*A020705; third column: A017029. - Vincenzo Librandi, Nov 18 2012

Examples

			Triangle begins:
12;
15, 20;
18, 25, 32;
21, 30, 39, 48;
24, 35, 46, 57, 68;
27, 40, 53, 66, 79, 92;
30, 45, 60, 75, 90, 105, 120;
33, 50, 67, 84, 101, 118, 135, 152; etc.
		

Links

• Vincenzo Librandi, Rows n = 1..100, flattened

Crossrefs

Cf. A153047, A020705, A017029.

Programs

Magma

[2*n*k+n+k+8: k in [1..n], n in [1..11]]; // Vincenzo Librandi, Nov 18 2012

Mathematica

Flatten[Table[2nm + m + n + 8, {n, 10}, {m, n}]] (* Vincenzo Librandi, Nov 18 2012 *)

Formula

T(n,m) = A163672(n,m)+1.

Extensions

Edited by R. J. Mathar, Oct 12 2009