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 A165949 a(n) = A027762(n)/A165734(n). 4
 1, 1, 7, 1, 11, 91, 1, 17, 133, 11, 23, 91, 1, 29, 2387, 17, 1, 63973, 1, 451, 301, 23, 47, 1547, 11, 53, 133, 29, 59, 1892891, 1, 17, 10787, 1, 781, 4670029, 1, 1, 553, 7667, 83, 113477, 1, 2047, 45353, 47, 1, 150059, 1, 1111, 721, 53, 107, 6973057, 253, 55709, 7 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS MAPLE A165734 := proc(n) op( 1+(n mod 2), [30, 6]) ; end: A027762 := proc(n) a := 0 ; p := 2 ; while p-1 <= 2*n do if (2*n) mod (p-1) = 0 then a := a+1/p ; fi; p := nextprime(p) ; od: denom(a) ; end: A165949 := proc(n) A027762(n)/A165734(n) ; end: seq(A165949(n), n=1..80) ; # R. J. Mathar, Oct 05 2009 MATHEMATICA a[n_] := Numerator[ Denominator[ BernoulliB[2*n, 1/2]]/(3*5*2^(2*n))]; Array[a, 57] (* Jean-François Alcover, Apr 17 2013, after Paul Curtz *) CROSSREFS Cf. A124886. Sequence in context: A074283 A331337 A211836 * A322565 A343227 A339965 Adjacent sequences: A165946 A165947 A165948 * A165950 A165951 A165952 KEYWORD nonn AUTHOR Paul Curtz, Oct 01 2009 EXTENSIONS Extended by R. J. Mathar, Oct 05 2009 STATUS approved

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Last modified March 31 21:40 EDT 2023. Contains 361673 sequences. (Running on oeis4.)