A073538 Let c(0)=n>=2 and c(k+1) = floor(3*c(k)/2); then a(n) is the smallest value such that c(a(n)) is prime.

0, 0, 3, 0, 2, 0, 12, 1, 5, 0, 11, 0, 2, 4, 6, 0, 10, 0, 3, 1, 3, 0, 5, 1, 93, 9, 5, 0, 2, 0, 35, 2, 17, 8, 4, 0, 3, 92, 8, 0, 4, 0, 6, 1, 2, 0, 34, 1, 13, 16, 7, 0, 3, 26, 4, 2, 91, 0, 7, 0, 2, 3, 7, 1, 5, 0, 3, 1, 2, 0, 33, 0, 4, 12, 15, 33, 6, 0, 5, 2, 25, 0, 3, 1, 2, 90, 19, 0, 6, 52, 7, 1, 2

Offset

2,3

Links

Table of n, a(n) for n=2..94.

Prog

(PARI) a(n)=if(n<0, 0, s=n; c=0; while(isprime(s)==0, s=floor(3*s/2); c++); c)

Crossrefs

Sequence in context: A065152 A344209 A171759 * A022898 A072780 A124452

Adjacent sequences: A073535 A073536 A073537 * A073539 A073540 A073541

Keyword

easy,nonn

Author

Benoit Cloitre, Aug 27 2002

Status

approved