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 A117436 Triangle related to exp(x)sec(2x). 2
 1, 0, 1, 4, 0, 1, 0, 12, 0, 1, 80, 0, 24, 0, 1, 0, 400, 0, 40, 0, 1, 3904, 0, 1200, 0, 60, 0, 1, 0, 27328, 0, 2800, 0, 84, 0, 1, 354560, 0, 109312, 0, 5600, 0, 112, 0, 1, 0, 3191040, 0, 327936, 0, 10080, 0, 144, 0, 1, 51733504, 0, 15955200, 0, 819840, 0, 16800, 0, 180, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 COMMENTS Row sums are A117437. Inverse is A117435. First column is A002436. Conjecture: The d-th diagonal (starting with d=0) is proportional to the sequence of generalized binomial coefficients binom(-x, d) where x is the column index. - Søren G. Have, Feb 26 2017 LINKS FORMULA Number triangle whose k-th column has e.g.f. (x^k/k!)*sec(2x). EXAMPLE 1, 0, 1, 4, 0, 1, 0, 12, 0, 1, 80, 0, 24, 0, 1, 0, 400, 0, 40, 0, 1, 3904, 0, 1200, 0, 60, 0, 1, 0, 27328, 0, 2800, 0, 84, 0, 1, 354560, 0, 109312, 0, 5600, 0, 112, 0, 1, 0, 3191040, 0, 327936, 0, 10080, 0, 144, 0, 1, 51733504, 0, 15955200, 0, 819840, 0, 16800, 0, 180, 0, 1 CROSSREFS Cf. A002436, A117435, A117437. Sequence in context: A117435 A282252 A268367 * A136448 A166318 A166317 Adjacent sequences:  A117433 A117434 A117435 * A117437 A117438 A117439 KEYWORD nonn,tabl AUTHOR Paul Barry, Mar 16 2006 STATUS approved

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