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A000061 Generalized tangent numbers.
(Formerly M0938 N0352)
+0
2
1, 1, 2, 4, 4, 6, 8, 8, 12, 14, 14, 16, 20, 20, 24, 32, 24, 30, 38, 32, 40, 46, 40, 48, 60, 50, 54, 64, 60, 68, 80, 64, 72, 92, 76, 96, 100, 82, 104, 112, 96, 108, 126, 112, 120, 148, 112, 128, 168, 130, 156, 160, 140, 162, 184, 160, 168, 198, 170, 192, 220, 168, 192 (list; graph; listen)
OFFSET

1,3

COMMENT

Comment from David W. Wilson, May 26 2007: If you look at the MathWorld article on Tangent Numbers, this sequence seems to give the initial terms of the sequences given in the table at the bottom of the article, which, in the nomenclature of the article, would translate to a(n) = d(n, 1) where d(a,n) is defined in equation (4), taken from the Shanks reference.

REFERENCES

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

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

Knuth, D. E.; Buckholtz, Thomas J. Computation of tangent, Euler and Bernoulli numbers. Math. Comp. 21 1967 663-688.

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

LINKS

Eric Weisstein's World of Mathematics, Tangent Number

CROSSREFS

Cf. A000176.

Adjacent sequences: A000058 A000059 A000060 this_sequence A000062 A000063 A000064

Sequence in context: A063200 A063224 A023847 this_sequence A153176 A112921 A008133

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

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

It would be nice to have a more precise definition! - N. J. A. Sloane (njas(AT)research.att.com), May 26, 2007

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Last modified November 7 16:45 EST 2009. Contains 166093 sequences.


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