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 A160469 The left hand column of the triangle A160468. 9
 1, 1, 2, 17, 62, 1382, 21844, 929569, 6404582, 443861162, 18888466084, 1936767361654, 58870668456604, 8374643517010684, 689005380505609448, 129848163681107301953, 1736640792209901647222, 418781231495293038913922 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Resembles A002430, the numerators of the Taylor series for tan(x). The first difference occurs at a(12). (Its resemblance to this sequence led to the conjecture A160469(n) = A002430(n)*A089170(n-1).) LINKS FORMULA a(n) = A002430(n)*A089170(n-1) with A002430 (n) = numer((-1)^(n-1)*2^(2*n)*(2^(2*n)-1)* bernoulli(2*n)/(2*n)!) and A089170 (n-1) = numer(2*bernoulli(2*n)* (4^n-1)/(2*n))/ numer((4^n-1)*bernoulli(2*n)/(2*n)!) for n = 1, 2, 3, .... CROSSREFS Equals the first left hand column of A160468. Equals A002430(n)*A089170(n-1). Equals (A002430(n)/A036279(n))*(A117972(n)/A000265(n)). Equals A048896(n-1)*A002425(n). Cf. A156769 (which resembles the denominators of the Taylor series for tan(x)). Sequence in context: A226417 A191295 A002430 * A176581 A303374 A037420 Adjacent sequences:  A160466 A160467 A160468 * A160470 A160471 A160472 KEYWORD easy,nonn AUTHOR Johannes W. Meijer, May 24 2009 STATUS approved

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Last modified January 22 16:37 EST 2020. Contains 331152 sequences. (Running on oeis4.)