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 A000508 Generalized class numbers. (Formerly M5324 N2315) 4
 61, 2763, 38528, 249856, 1066590, 3487246, 9493504, 22634496, 48649086, 96448478, 179369856, 315621376, 530788622, 860061996, 1346126848, 2046820352, 3038120316, 4403100222, 6254596992, 8737505280, 11992903772 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 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 D. Shanks, Generalized Euler and class numbers, Math. Comp. 21 1967 6890694. D. Shanks, Corrigenda to: "Generalized Euler and class numbers", Math. Comp. 22 (1968), 699 D. Shanks, Generalized Euler and class numbers, Math. Comp. 21 (1967), 689-694; 22 (1968), 699. [Annotated scanned copy] MATHEMATICA amax = 25; km0 = 10; Clear[cc]; L[a_, s_, km_] := Sum[ JacobiSymbol[ -a, 2 k + 1]/(2 k + 1)^s, {k, 0, km}]; c[1, n_, km_] := 2 (2 n)! L[1, 2 n + 1, km] (2/Pi)^(2 n + 1) // Round; c[a_ /; a > 1, n_, km_] := (2 n)! L[a, 2 n + 1, km] (2 a/Pi)^(2 n + 1)/Sqrt[a] // Round; cc[km_] := cc[km] = Table[ c[a, 3, km], {a, 1, amax} ]; cc[km0]; cc[km = 2 km0]; While[cc[km] != cc[km/2, km = 2 km]]; A000508 = cc[km] (* Jean-François Alcover, Feb 09 2016 *) CROSSREFS Cf. A000003, A000233, A000362. Sequence in context: A038650 A224441 A078962 * A191092 A234028 A135647 Adjacent sequences:  A000505 A000506 A000507 * A000509 A000510 A000511 KEYWORD nonn,easy AUTHOR EXTENSIONS More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Jun 02 2000 STATUS approved

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Last modified February 20 12:57 EST 2019. Contains 320327 sequences. (Running on oeis4.)