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A097698 Numbers n such that both 4*n^2 - 3 and 4*n^2 + 3 are primes. 6
2, 4, 5, 7, 32, 46, 56, 70, 73, 86, 109, 149, 152, 161, 163, 170, 175, 178, 208, 220, 235, 254, 277, 280, 290, 313, 317, 326, 334, 343, 347, 352, 364, 368, 373, 385, 403, 409, 434, 446, 460, 527, 541, 551, 565, 578, 598, 628, 632, 689, 709, 710, 737, 761, 812 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

FORMULA

a(n) = A153975(n) / 2. - Vladimir Joseph Stephan Orlovsky, Apr 23 2010

MATHEMATICA

Select[Range[0, 7! ], PrimeQ[ #^2-3]&&PrimeQ[ #^2+3]&]/2 (* Vladimir Joseph Stephan Orlovsky, Apr 23 2010 *)

PROG

(MAGMA) [n: n in [1..1000] |IsPrime(4*n^2-3) and IsPrime(4*n^2+3)] // Vincenzo Librandi, Nov 16 2010

(PARI) is(n)=isprime(4*n^2-3) && isprime(4*n^2+3) \\ Charles R Greathouse IV, Sep 27 2016

CROSSREFS

Cf. A083022, A097697, A153975.

Sequence in context: A244332 A119909 A301521 * A233524 A324331 A101410

Adjacent sequences:  A097695 A097696 A097697 * A097699 A097700 A097701

KEYWORD

easy,nonn

AUTHOR

Carl R. White, Aug 20 2004

STATUS

approved

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Last modified November 20 20:56 EST 2019. Contains 329347 sequences. (Running on oeis4.)