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A180418 ( A000111(p) -(-1)^((p-1)/2) )/p, where p = prime(n). 2
1, 3, 39, 32163, 1720635, 12345020175, 1530993953307, 44148864630732711, 797213247855503373843915, 281095572810489332134542303, 26242778669866462496740532647355475 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

COMMENTS

See the formula in A000111.

LINKS

Table of n, a(n) for n=2..12.

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

Cf. A000040, A000111.

Sequence in context: A076628 A198411 A097421 * A166999 A319955 A317484

Adjacent sequences:  A180415 A180416 A180417 * A180419 A180420 A180421

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

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Last modified May 14 16:48 EDT 2021. Contains 343898 sequences. (Running on oeis4.)