OFFSET
1,1
COMMENTS
LINKS
Eric Weisstein's World of Mathematics, Andrica's conjecture
FORMULA
Conjecture: there is a constant c>0 such that for n large enough, a(n)>c*sqrt(n) and we can take c=0.4. More precisely, there are 2 constants A and B such that A=lim sup n ->infinity a(n)/sqrt(n) exists = 0.75....; B=lim inf n ->infinity a(n)/sqrt(n) exists =0.46....
PROG
(PARI) a(n)=if(n<0, 0, k=1; while(abs(sqrt(prime(n+k))-sqrt(prime(n)))<1, k++); k)
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Feb 02 2003
STATUS
approved