A184803 Numbers k such that floor(k*sqrt(5)) is prime.

1, 5, 6, 8, 13, 14, 24, 30, 32, 33, 40, 48, 49, 57, 59, 67, 73, 75, 81, 89, 100, 107, 108, 115, 118, 124, 126, 127, 140, 142, 151, 158, 167, 174, 183, 193, 194, 201, 209, 218, 220, 225, 228, 233, 234, 242, 245, 252, 268, 269, 276, 277, 287, 288, 295, 296, 301, 303, 328, 336, 344, 346, 352, 362, 363, 370, 371, 386, 394, 395, 397, 406, 411, 421, 437, 440, 446, 456, 457, 462, 465, 488, 489, 491, 496, 505, 515, 516, 524, 531, 547, 550, 559, 572, 574, 582, 583, 590, 591

Offset

1,2

Links

Table of n, a(n) for n=1..99.

Example

See A184802.

Mathematica

(See A184802.)
With[{c=Sqrt[5]}, Select[Range[600], PrimeQ[Floor[# c]]&]] (* Harvey P. Dale, Jul 20 2011 *)

Prog

(PARI) is(n)=isprime(sqrtint(5*n^2)) \\ Charles R Greathouse IV, May 22 2017

Crossrefs

Cf. A022839, A184802, A184803, A184804.

Sequence in context: A047437 A188054 A276374 * A331264 A096467 A334120

Adjacent sequences: A184800 A184801 A184802 * A184804 A184805 A184806

Keyword

nonn

Author

Clark Kimberling, Jan 22 2011

Status

approved