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A104634
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Triangle T(n,k) = (k-1-n)*(k-2-n)*(k+2*n)/6, 1<=k<=n.
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2
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1, 5, 2, 14, 8, 3, 30, 20, 11, 4, 55, 40, 26, 14, 5, 91, 70, 50, 32, 17, 6, 140, 112, 85, 60, 38, 20, 7, 204, 168, 133, 100, 70, 44, 23, 8, 285, 240, 196, 154, 115, 80, 50, 26, 9, 385, 330, 276, 224, 175, 130, 90, 56, 29, 10, 506, 440, 375, 312, 252, 196, 145, 100, 62, 32, 11, 650, 572, 495, 420, 348, 280, 217, 160, 110, 68, 35, 12, 819, 728, 638, 550, 465, 384
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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FORMULA
| The triangle is created by the matrix product A002260 * A004736, both infinite lower triangular matrices.
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EXAMPLE
| The first few rows are:
1;
5, 2;
14, 8, 3;
30, 20, 11, 4;
55, 40, 26, 14, 5;
91, 70, 50, 32, 17, 6;
...
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MAPLE
| A104634 := proc(n, k) (k-1-n)*(k-2-n)*(k+2*n)/6 ; end proc:
seq(seq(A104634(n, k), k=1..n), n=1..15) ; # R. J. Mathar, Aug 31 2011
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CROSSREFS
| Cf. A000330 (column 1), A007290 (column 2), A051925 (column 3), A001296 (row sums), A104633, A000332.
Sequence in context: A085436 A194048 A158868 * A194008 A060422 A185781
Adjacent sequences: A104631 A104632 A104633 * A104635 A104636 A104637
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KEYWORD
| nonn,tabl,easy
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AUTHOR
| Gary W. Adamson (qntmpkt(AT)yahoo.com), Mar 18 2005
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EXTENSIONS
| Definition in closed form provided by R. J. Mathar, Aug 31 2011
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