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A157000
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Triangle T(n,k) = (n/k)*binomial(n-k-1, k-1) read by rows.
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1
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2, 3, 4, 2, 5, 5, 6, 9, 2, 7, 14, 7, 8, 20, 16, 2, 9, 27, 30, 9, 10, 35, 50, 25, 2, 11, 44, 77, 55, 11, 12, 54, 112, 105, 36, 2, 13, 65, 156, 182, 91, 13, 14, 77, 210, 294, 196, 49, 2, 15, 90, 275, 450, 378, 140, 15, 16, 104, 352, 660, 672, 336, 64, 2, 17, 119, 442, 935, 1122, 714
(list; graph; refs; listen; history; internal format)
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OFFSET
| 2,1
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COMMENTS
| Row sums are A001610(n-1).
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REFERENCES
| J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, pp. 199
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EXAMPLE
| The table starts in row n=2, column k=1 as:
2;
3;
4, 2;
5, 5;
6, 9, 2;
7, 14, 7;
8, 20, 16, 2;
9, 27, 30, 9;
10, 35, 50, 25, 2;
11, 44, 77, 55, 11;
12, 54, 112, 105, 36, 2;
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MATHEMATICA
| g[n_, k_] := (n/k)*Binomial[n - k - 1, k - 1];
Table[Table[g[n, k + 1], {k, 0, Floor[n/2] - 1}], {n, 12}];
Flatten[%]
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PROG
| (PARI) a(n, k)=n*binomial(n-k-1, k-1)/k \\ Charles R Greathouse IV, Jul 10 2011
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CROSSREFS
| Cf. A132460, A113279, A082985.
Sequence in context: A100798 A121701 A161759 * A026346 A120636 A117744
Adjacent sequences: A156997 A156998 A156999 * A157001 A157002 A157003
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KEYWORD
| nonn,easy,tabf
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AUTHOR
| Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Feb 20 2009
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EXTENSIONS
| Offset 2, keyword:tabf, more terms by the Assoc. Eds. of the OEIS, Nov 01 2010.
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