login
Numbers k such that floor(k*log(k)) is prime.
1

%I #16 May 23 2022 11:44:28

%S 3,4,7,9,10,12,20,29,65,67,72,73,86,93,97,98,107,117,140,143,146,147,

%T 148,150,151,153,156,182,183,186,192,194,205,206,207,211,227,228,235,

%U 236,241,248,249,253,259,270,273,279,283,289,292,298,325,330,347,352

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

%H Amiram Eldar, <a href="/A066928/b066928.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Harry J. Smith)

%t Select[Range[400], PrimeQ[Floor[# * Log[#]]] &] (* _Amiram Eldar_, May 23 2022 *)

%o (PARI) { n=0; for (m=1, 10^10, if (isprime(floor(m*log(m))), write("b066928.txt", n++, " ", m); if (n==1000, return)) ) } \\ _Harry J. Smith_, Apr 07 2010

%K nonn

%O 1,1

%A _Benoit Cloitre_, Jan 23 2002