[go: up one dir, main page]

login
A176616
Primes of the form x^2 + 7*y^2, where x and y=x+1 are consecutive natural numbers.
5
7, 29, 67, 191, 277, 379, 631, 947, 1129, 1327, 2017, 2557, 2851, 4561, 4951, 5779, 6217, 8647, 9181, 12721, 13367, 14029, 15401, 16111, 17579, 20707, 21529, 22367, 24091, 24977, 31627, 36857, 37951, 42487, 43661, 44851, 47279, 53629, 58997
OFFSET
1,1
COMMENTS
Primes of the form 8*n^2+14*n+7 = (2*n+2)*(4*n+3)+1 = A000384(2*n+2)+1. - Vincenzo Librandi, Apr 25 2010
LINKS
MATHEMATICA
Select[Table[x^2+7(x+1)^2, {x, 0, 100}], PrimeQ] (* Harvey P. Dale, May 03 2024 *)
PROG
(Magma) [ a: n in [0..250] | IsPrime(a) where a is 8*n^2+14*n+7 ] // Vincenzo Librandi, Apr 25 2010
CROSSREFS
Cf. A176608.
A285790 is an almost identical sequence.
Sequence in context: A022272 A185438 A265803 * A231988 A141854 A267290
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, Apr 22 2010
EXTENSIONS
Definition made more accurate by R. J. Mathar, May 04 2010
Corrected (inserted 7) and extended by Vincenzo Librandi, Apr 25 2010
Offset corrected by Mohammed Yaseen, May 20 2023
STATUS
approved