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A180418
a(n) = ( A000111(p) -(-1)^((p-1)/2) )/p, where p = prime(n).
3
1, 3, 39, 32163, 1720635, 12345020175, 1530993953307, 44148864630732711, 797213247855503373843915, 281095572810489332134542303, 26242778669866462496740532647355475
OFFSET
2,2
LINKS
FORMULA
a(n) = ( A000111(A000040(n)) -A070750(n) )/A000040(n). - R. J. Mathar, Sep 19 2010
MATHEMATICA
t = Range[0, 60]! CoefficientList[Series[Sec@x + Tan@x, {x, 0, 60}], x]; f[n_] := (Rest[t][[Prime@n]] - (-1)^((Prime@n - 1)/2))/Prime@n; Array[f, 11, 2] (* Robert G. Wilson v, Sep 04 2010 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Sep 03 2010
EXTENSIONS
Extended by R. J. Mathar, Sep 19 2010
a(8) onwards from Robert G. Wilson v, Sep 04 2010
STATUS
approved