A000176 Generalized tangent numbers d_(n,2). (Formerly M2001 N0791)

2, 11, 46, 128, 272, 522, 904, 1408, 2160, 3154, 4306, 5888, 7888, 10012, 12888, 16384, 19680, 24354, 29866, 34816, 41888, 49778, 56744, 66816, 78000, 87358, 100602, 115712, 128112, 145804, 165712, 180224, 203040, 228964, 246932, 276480

Offset

1,1

Comments

Consider the Dirichlet series L_a(s) = sum_{k>=0} (-a|2k+1) / (2k+1)^s, where (-a|2k+1) is the Jacobi symbol. Then the numbers d_(a,n) are defined by L_a(2n)= (Pi/(2a))^(2n)*sqrt(a)* d_(a,n)/ (2n-1)! for a>1 and n=1,2,3...

References

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Sean A. Irvine, Table of n, a(n) for n = 1..10000

D. Shanks, Generalized Euler and class numbers. Math. Comp. 21 (1967) 689-694.

D. Shanks, Corrigenda to: "Generalized Euler and class numbers", Math. Comp. 21 (1967), 689-694; 22 (1968), 699.

Crossrefs

Cf. A000061 for d_(n,1), A000488 for d_(n,3), A000518 for d_(n,4).

Sequence in context: A037751 A037639 A319428 * A042927 A292533 A140305

Adjacent sequences: A000173 A000174 A000175 * A000177 A000178 A000179

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jun 03 2000

Status

approved