A171079 Denominator of s_{2n}, where s_0 = 1/2, s_n = | 2^n*(2^(n-1)-1)*Bernoulli(n)/n! | for n>0.

2, 3, 45, 945, 4725, 13365, 638512875, 18243225, 23260111875, 38979295480125, 1531329465290625, 274446060013125, 201919571963756521875, 11094481976030578125, 80664808595725181953125, 5660878804669082674070015625, 31245110285511170603633203125, 75344438393998438430390625

Offset

0,1

References

F. Hirzebruch, Topological Methods in Algebraic Geometry, Springer, 3rd. ed., 1966; p. 12, Eq. 11.

Links

Table of n, a(n) for n=0..17.

Formula

a(n) = denominator(Zeta(2*n)*(4^n-2)/Pi^(2*n)). - Peter Luschny, Aug 11 2014

Example

1/2, 1/3, 7/45, 62/945, 127/4725, 146/13365, 2828954/638512875, 32764/18243225, 16931177/23260111875, 11499383114/38979295480125, ...

Maple

A171079 := n -> denom(Zeta(2*n)*(4^n-2)/Pi^(2*n));
seq(A171079(n), n=0..17); # Peter Luschny, Aug 11 2014

Crossrefs

Cf. A171078 (numerators).

Sequence in context: A060415 A289661 A191996 * A097929 A266512 A041501

Adjacent sequences: A171076 A171077 A171078 * A171080 A171081 A171082

Keyword

nonn,frac

Author

N. J. A. Sloane, Sep 06 2010

Extensions

a(0) changed in accordance with the zeta based formula. Peter Luschny, Aug 18 2014

Status

approved