A225845 Numerator of c(n) = 2^(2*n)*(2^(2*n) - 1)/(2*n)!, a coefficient used in the expansion of tan(x) as Sum_{n>=1} c(n)*|Bernoulli(2*n)|*x^(2*n-1).

0, 6, 10, 28, 34, 1364, 52, 43688, 8738, 5548, 5084, 11184808, 964, 178956968, 143165576, 24790576, 33686018, 22906492244, 1177636, 733007751848, 10115684, 79783156664, 407934748856, 375299968947536, 16173237188, 8804691353608, 2401919801264264

Offset

0,2

References

George Boros and Victor H. Moll, Irresistible integrals, Cambridge University Press (2006), p. 63.

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..300

Mathematica

Table[2^(2*n)*(2^(2*n)-1)/(2*n)! // Numerator, {n, 0, 30}]

Prog

(Magma) [Numerator(2^(2*n)*(2^(2*n)-1)/Factorial(2*n)): n in [0..30]]; // Vincenzo Librandi, Jul 17 2013

Crossrefs

Cf. A225846 (denominators), A000367, A002445, A002430, A036279.

Sequence in context: A081394 A184387 A295185 * A014494 A318894 A129545

Adjacent sequences: A225842 A225843 A225844 * A225846 A225847 A225848

Keyword

nonn,frac,easy

Author

Jean-François Alcover, May 17 2013

Status

approved