OFFSET
1,1
COMMENTS
EXAMPLE
MATHEMATICA
Select[Prime@Range@200, EvenQ@ First@ DigitCount[3#-1, 2] &] (* Giovanni Resta, Jan 26 2014 *)
PROG
(PARI) isok(p) = isprime(p) && !(hammingweight(3*p-1) % 2); \\ Michel Marcus, Jan 18 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Juri-Stepan Gerasimov, Jan 17 2014
STATUS
approved