|
|
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*k^2 + 10*k + 5 or 2*k^2 - 6*k - 3. - Vincenzo Librandi, Apr 19 2010
|
|
LINKS
|
|
|
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
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|