OFFSET
1,4
PROG
(PARI) a(n)=if(n<0, 0, s=n; c=1; while(isprime(ceil(3*s/2))==0, s=ceil(3*s/2); c++); c)
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Dec 17 2002
STATUS
approved