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A176470 Primes of the form 5*x^2-3*y^2, where x and y are consecutive numbers. 4
5, 17, 53, 137, 173, 257, 677, 1097, 1193, 1733, 2237, 2657, 2957, 4133, 5297, 5717, 8573, 8837, 9377, 11093, 11393, 12953, 14957, 17477, 18233, 18617, 19793, 23537, 24413, 29033, 30497, 33533, 36713, 40037, 41177, 45293, 48353 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(n) is congruent to 1 mod 4.

Primes of the form 2*n^2+10*n+5 or 2*n^2-6*n-3. [From Vincenzo Librandi, Apr 19 2010]

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

MATHEMATICA

Select[Table[5n^2-3(n+1)^2, {n, 4, 200}], PrimeQ] (* Harvey P. Dale, Aug 07 2017 *)

PROG

(MAGMA) [ p: p in PrimesUpTo(60000) | exists(t){ n: n in [1..Isqrt(p)] | p eq 5*n^2-3*(n-1)^2 } ]; //y = x-1

CROSSREFS

Sequence in context: A191139 A107167 A201478 * A240693 A278464 A186254

Adjacent sequences:  A176467 A176468 A176469 * A176471 A176472 A176473

KEYWORD

nonn

AUTHOR

Giovanni Teofilatto, Apr 18 2010

EXTENSIONS

Corrected the comment. - Giovanni Teofilatto, Apr 19 2010

STATUS

approved

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Last modified August 7 12:13 EDT 2020. Contains 336276 sequences. (Running on oeis4.)