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A137251
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Triangle T(n,k) read by rows: number of k X k triangular matrices with nonnegative integer entries and without zero rows or columns such that sum of all entries is equal to n, n>=1, 1<=k<=n.
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0
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1, 1, 1, 1, 3, 1, 1, 6, 7, 1, 1, 10, 26, 15, 1, 1, 15, 71, 98, 31, 1, 1, 21, 161, 425, 342, 63, 1, 1, 28, 322, 1433, 2285, 1138, 127, 1, 1, 36, 588, 4066, 11210, 11413, 3670, 255, 1, 1, 45, 1002, 10165, 44443, 79781, 54073, 11586, 511, 1, 1, 55, 1617, 23056, 150546
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,5
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EXAMPLE
| 1
1,1
1,3,1
1,6,7,1
1,10,26,15,1
1,15,71,98,31,1
1,21,161,425,342,63,1
1,28,322,1433,2285,1138,127,1
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CROSSREFS
| Cf. (row sums)A022493.
Sequence in context: A133713 A008278 A056858 * A158359 A046716 A202605
Adjacent sequences: A137248 A137249 A137250 * A137252 A137253 A137254
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KEYWORD
| nonn,tabl
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AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Mar 11 2008
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