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 A008308 Triangle of tangent numbers. 1
 1, 1, 2, 1, 8, 1, 16, 20, 1, 136, 40, 1, 272, 616, 70, 1, 3968, 2016, 112, 1, 7936, 28160, 5376, 168, 1, 176896, 135680, 12432, 240, 1, 353792, 1805056, 508640, 25872, 330, 1, 11184128, 11977856, 1595264, 49632, 440, 1, 22368256, 154918400, 59835776 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 REFERENCES L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 259. LINKS EXAMPLE Triangle begins:     1;     1;     2,  1;     8,  1;    16, 20, 1;   136, 40, 1;   ... MATHEMATICA T[n_, n_] = 1; T[n_, k_] /; 0 <= k <= n := T[n, k] = T[n - 1, k - 1] + k*(k + 1)*T[n - 1, k + 1]; T[_, _] = 0; row[n_] := DeleteCases[Table[T[n, k], {k, 1, n}] , 0]; Array[row, 13] // Flatten (* Jean-François Alcover, Nov 09 2017 *) CROSSREFS Essentially the same triangle as A059419, which is the main entry for this triangle. Row sums give A006229. Sequence in context: A102208 A125911 A009385 * A176889 A208753 A118931 Adjacent sequences:  A008305 A008306 A008307 * A008309 A008310 A008311 KEYWORD tabf,nonn,nice AUTHOR EXTENSIONS More terms from Larry Reeves (larryr(AT)acm.org), Feb 08 2001 STATUS approved

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Last modified January 24 05:51 EST 2019. Contains 319415 sequences. (Running on oeis4.)