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 A000176 Generalized tangent numbers d_(n,2). (Formerly M2001 N0791) 5
 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 (list; graph; refs; listen; history; text; internal format)
 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 663-688. 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: A120279 A037751 A037639 * A042927 A292533 A140305 Adjacent sequences:  A000173 A000174 A000175 * A000177 A000178 A000179 KEYWORD nonn AUTHOR EXTENSIONS More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jun 03 2000 STATUS approved

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