OFFSET
1,2
COMMENTS
Conjectures: (Strong) Let x,y be 2 positive integers and define a(n) as a(1)=1, a(n)=x*a(n-1) if a(n-1) is prime, a(n)=a(n-1)+y otherwise; then lim_{n->oo} log(a(n))/sqrt(n) = C(x,y) exists. (Weak) log(a(n))/sqrt(n) is bounded.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
It seems that log(a(n))/sqrt(n) -> C, a constant around 1.3.....
a(n) = A055496(m) when a(n+1) > a(n) + 1. - Bill McEachen, Mar 24 2024
MATHEMATICA
NestList[If[PrimeQ[#], 2#, #+1]&, 1, 50] (* Harvey P. Dale, Aug 26 2013 *)
PROG
(PARI) u=1; for(n=2, 100, v=if(isprime(u), u+1, 2*u); u=v; print1(v, ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Mar 08 2003
STATUS
approved