A155724 - OEIS

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A155724

Triangle read by rows: T(m,n) = 2mn + m + n - 4.

0, 3, 8, 6, 13, 20, 9, 18, 27, 36, 12, 23, 34, 45, 56, 15, 28, 41, 54, 67, 80, 18, 33, 48, 63, 78, 93, 108, 21, 38, 55, 72, 89, 106, 123, 140, 24, 43, 62, 81, 100, 119, 138, 157, 176, 27, 48, 69, 90, 111, 132, 153, 174, 195, 216, 30, 53, 76, 99, 122, 145, 168, 191, 214, 237, 260

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

2*T(m,n)+9 = (2m+1)*(2n+1). - Vincenzo Librandi, Nov 18 2012

First column: A008585; second column: A016885; third column: A017053; fourth column: 9*A020705. - Vincenzo Librandi, Nov 18 2012

LINKS

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

FORMULA

T(m,n) = A154685(m,n) - 8. - L. Edson Jeffery, Oct 12 2012

EXAMPLE

Triangle begins:

3, 8;

6, 13, 20;

9, 18, 27, 36;

12, 23, 34, 45, 56;

15, 28, 41, 54, 67, 80;

18, 33, 48, 63, 78, 93, 108;

21, 38, 55, 72, 89, 106, 123, 140;

24, 43, 62, 81, 100, 119, 138, 157, 176;

27, 48, 69, 90, 111, 132, 153, 174, 195, 216;

MATHEMATICA

Flatten[Table[2 n m + m + n - 4, {n, 10}, {m, n}]] (* Vincenzo Librandi, Mar 01 2012 *)

PROG

(Magma) /* Triangle: */ [[2*m*n+m+n-4: m in [1..n]]: n in [1..10]]; // Bruno Berselli, Aug 31 2012

CROSSREFS

All terms are in A155723.

Cf. A154685, A155722, A162261 (row sums), A008585, A016885, A017053, A020705.

Sequence in context: A371472 A295573 A080939 * A289485 A304299 A221951

Adjacent sequences: A155721 A155722 A155723 * A155725 A155726 A155727

KEYWORD

nonn,tabl,easy

AUTHOR

Vincenzo Librandi, Jan 25 2009

EXTENSIONS

Edited by N. J. A. Sloane, Jun 23 2010

STATUS

approved