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A074381 (p-1)/2 mod 2, where p is the n-th prime for which p+2 is also prime; i.e., a(n)=0 if p==1 (mod 4), a(n)=1 if p==3 (mod 4). 0
1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..105.

MATHEMATICA

Mod[(Select[Prime/@Range[600], PrimeQ[ #+2]&]-1)/2, 2]

CROSSREFS

Cf. A001359, A071695, A071698.

Sequence in context: A266282 A228747 A285162 * A179560 A128407 A134286

Adjacent sequences:  A074378 A074379 A074380 * A074382 A074383 A074384

KEYWORD

nonn,easy

AUTHOR

Roger L. Bagula, Sep 24 2002

EXTENSIONS

Edited by Dean Hickerson and Robert G. Wilson v, Oct 09 2002

STATUS

approved

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Last modified September 21 22:12 EDT 2019. Contains 327284 sequences. (Running on oeis4.)