OFFSET
1,10
COMMENTS
Conjecture : for n > 1000 a(n) - n/2 < - sqrt(n) ( if b(n) denotes the number of x with largest prime factor of the form 4k+3 less than or equal to n, it is conjectured that if n > 1000 b(n)- n/2 > sqrt(n) )
PROG
(PARI) a(n)=sum(i=2, n, (factor(i)[omega(i), 1])-1)%4==0)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Jun 07 2002
EXTENSIONS
Missing a(1)=0 inserted by Sean A. Irvine, Aug 15 2024
STATUS
approved