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A140733
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Triangle read by rows, X^n * [1,0,0,0,...]; where X = a tridiagonal matrix with (1,1,1,...) in the main and subdiagonals and (1,2,3,...) in the subsubdiagonal.
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2
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1, 1, 1, 1, 1, 2, 3, 3, 3, 1, 3, 6, 10, 15, 15, 15, 1, 4, 10, 22, 43, 70, 105, 105, 105, 1, 5, 15, 40, 95, 201, 390, 630, 945, 945, 945, 1, 6, 21, 65, 180, 456, 1066, 2226, 4305, 6930, 10395, 10395, 10395, 1, 7, 28, 98, 308, 896, 2422, 6028, 13993, 29043, 56070, 90090
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,6
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COMMENTS
| Rightmost terms of each row form A001147: (1, 1, 3, 15, 105, 945,...).
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EXAMPLE
| First few rows of the triangle are:
1;
1, 1, 1;
1, 2, 3, 3, 3;
1, 3, 6, 10, 15, 15, 15;
1, 4, 10, 22, 43, 70, 105, 105, 105;
1, 5, 15, 40, 95, 201, 390, 630, 945, 945, 945;
1, 6, 21, 65, 180, 456, 1066, 2226, 4305, 6930, 10395, 10395, 10395;
...
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CROSSREFS
| Cf. A140734, A140735, A001147.
Sequence in context: A061911 A082239 A062745 * A143605 A098418 A128080
Adjacent sequences: A140730 A140731 A140732 * A140734 A140735 A140736
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KEYWORD
| nonn,tabl
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AUTHOR
| Gary W. Adamson & Roger L. Bagula (qntmpkt(AT)yahoo.com), May 25 2008
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