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 A273352 a(n) = 2^(2n+2) F(n) where F(n) is Ramanujan's F(n) = Sum_{k>=1} k^(4n-1)/(e^(Pi*k)-1) - 16^n* Sum_{k>=1} k^(4n-1)/(e^(4*Pi*k)-1). 5
 1, 34, 11056, 14873104, 56814228736, 495812444583424, 8575634961418940416, 265929039218907754399744, 13722623393637762299131396096, 1112372064432735526930220874072064, 135292015985218004848567636630910795776, 23782283324940089109797537284278352042000384 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Bisection of the reduced tangent numbers, A002105. This follows from the formulas. - Franklin T. Adams-Watters, May 22 2016 LINKS Math.Stackexchange.Com, Marko R. Riedel et al., Closed form of a sum by Ramanujan FORMULA a(n) = 2^{2*n+2} * Bernoulli(4*n) * (1-2^(4*n))/(8*n). MAPLE S := proc(n, k) option remember; if k=0 then `if`(n=0, 1, 0) else S(n, k-1) + S(n-1, n-k) fi end: A273352 := n -> S(4*n-1, 4*n-1)/2^(2*n-1): seq(A273352(n), n=1..12); # Peter Luschny, Jan 18 2017 MATHEMATICA Table[2^(2*n + 2)*BernoulliB[4*n]*(1 - 2^(4*n))/(8*n), {n, 1, 10}] (* G. C. Greubel, May 21 2016 *) (* Function LMLlist defined in A293951 *) LMLlist[4, 13] (* Peter Luschny, Aug 26 2018 *) CROSSREFS Cf. A002105. Cf. A000182 (m=2), A293951 (m=3), this seq (m=4), A318258 (m=5). Sequence in context: A005334 A033511 A246240 * A189448 A214368 A328293 Adjacent sequences:  A273349 A273350 A273351 * A273353 A273354 A273355 KEYWORD nonn AUTHOR Marko Riedel, May 20 2016 STATUS approved

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Last modified October 17 11:59 EDT 2019. Contains 328110 sequences. (Running on oeis4.)