login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A184803 Numbers k such that floor(k*sqrt(5)) is prime. 3

%I #16 Apr 21 2021 04:25:39

%S 1,5,6,8,13,14,24,30,32,33,40,48,49,57,59,67,73,75,81,89,100,107,108,

%T 115,118,124,126,127,140,142,151,158,167,174,183,193,194,201,209,218,

%U 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

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

%e See A184802.

%t (See A184802.)

%t With[{c=Sqrt[5]},Select[Range[600],PrimeQ[Floor[# c]]&]] (* _Harvey P. Dale_, Jul 20 2011 *)

%o (PARI) is(n)=isprime(sqrtint(5*n^2)) \\ _Charles R Greathouse IV_, May 22 2017

%Y Cf. A022839, A184802, A184803, A184804.

%K nonn

%O 1,2

%A _Clark Kimberling_, Jan 22 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 11:46 EDT 2024. Contains 371241 sequences. (Running on oeis4.)