A003414 a(n) = floor( Bernoulli(2*n)/(-4*n) ).

-1, 0, -1, 0, -1, 0, -1, 0, -2, 13, -141, 1803, -27414, 487468, -10026348, 236192433, -6317862398, 190439655626, -6425425249653, 241207241774250, -10020155328258127, 458387180159766538, -22989944171828251746, 1259023596072554784854, -75008667460769643668558

Offset: 1

Author

N. J. A. Sloane

Keywords

• sign

Examples

			a(10) = 13 because the 20th (2 * 10) Bernoulli number is -174611/330, and that divided by (-4) * 10 is approximately 13.2281.
		

References

• F. Hirzebruch et al., Manifolds and Modular Forms, Vieweg, 2nd ed. 1994, p. 130.
• D. C. Ravenel, Complex cobordism theory for number theorists, Lecture Notes in Mathematics, 1326, Springer-Verlag, Berlin-New York, 1988, pp. 123-133.

Links

• T. D. Noe, Table of n, a(n) for n = 1..100
• Index entries for sequences related to Bernoulli numbers.

Crossrefs

Cf. A000367/A002445.

Programs

Mathematica

Table[Floor[BernoulliB[2n]/(-4n)], {n, 24}] (* Alonso del Arte, Jul 11 2012 *)