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A064190
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Triangle T(n,k) generalizing the tangent numbers.
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2
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1, 2, 6, 16, 48, 72, 272, 816, 1440, 1440, 7936, 23808, 44352, 57600, 43200, 353792, 1061376, 2027520, 2903040, 3024000, 1814400, 22368256, 67104768, 129964032, 195379200, 232243200, 203212800, 101606400, 1903757312, 5711271936
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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LINKS
| J. L. Arregui, Tangent and Bernoulli numbers related to Motzkin and Catalan numbers by means of numerical triangles.
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FORMULA
| T(n+1, m) = m*(m+1)*Sum_{k = m-1, n} T(n, k)
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EXAMPLE
| 1; 2,6; 16,48,72; 272,816,1440,1440; ...
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CROSSREFS
| First column gives A000182.
If m*(m+1) is replaced in the formula by m*m, the first column is the sequence of secant numbers A000364. - Jose L. Arregui (arregui(AT)posta.unizar.es), Oct 09 2001
Sequence in context: A071726 A148443 A148444 * A151281 A045694 A129772
Adjacent sequences: A064187 A064188 A064189 * A064191 A064192 A064193
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KEYWORD
| nonn,tabl,easy,nice
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Sep 21 2001
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EXTENSIONS
| More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 22 2001
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