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A180419 ( A000111(2*p)-1 )/( 2*p), where p = A000040(n) = prime(n). 0
1, 10, 5052, 14240070, 3152221563324450, 157195096511273995860, 2374214683408467590063771983920, 618146855974818638210995488847340730, 144946467754033586465978879886385830380958862710 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

My comment in A000111 concerning A000111(2*p) mod (2*p) says that all entries are integers.

LINKS

Table of n, a(n) for n=1..9.

MATHEMATICA

t = Range[0, 60]! CoefficientList[ Series[ Sec@x + Tan@x, {x, 0, 60}], x]; f[n_] := (Rest[t][[2 Prime@n]] - 1)/(2 Prime@n); Array[f, 9] (* Robert G. Wilson v, Sep 04 2010 *)

CROSSREFS

Cf. A180418, A000111, A180417.

Sequence in context: A273415 A223055 A308488 * A061888 A117803 A199520

Adjacent sequences:  A180416 A180417 A180418 * A180420 A180421 A180422

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, Sep 03 2010

EXTENSIONS

a(6) onwards from Robert G. Wilson v, Sep 04 2010

Definition rephrased by R. J. Mathar, Sep 29 2010

STATUS

approved

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Last modified April 19 05:00 EDT 2021. Contains 343105 sequences. (Running on oeis4.)