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A117849 a(n) =(A001359[n]^2-1)/2 0
2, 6, 30, 72, 210, 420, 870, 1260, 2550, 2862, 4692, 5550, 8010, 9120, 9702, 12882, 14280, 18090, 19740, 24180, 30102, 43890, 46440, 53130, 67860, 80940, 89700, 95172, 102720, 108570, 163620, 168510, 170982, 183612, 194040, 259590, 265740 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

A sequence determined by the quadratic reciprocity power of twin primes:A001359.

LINKS

Table of n, a(n) for n=0..36.

MATHEMATICA

f[n_] = If[Prime[n + 1] - Prime[n] - 2 == 0, Prime[n], {}] a = Flatten[Table[(f[n]^2 - 1)/4, {n, 1, 200}]]

CROSSREFS

Cf. A001359.

Sequence in context: A008341 A211889 A174276 * A328417 A290760 A088857

Adjacent sequences:  A117846 A117847 A117848 * A117850 A117851 A117852

KEYWORD

nonn

AUTHOR

Roger L. Bagula, May 01 2006

STATUS

approved

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Last modified August 10 08:28 EDT 2020. Contains 336368 sequences. (Running on oeis4.)