OFFSET
1,2
COMMENTS
LINKS
FORMULA
PROG
(PARI) A331304(n) = if(n<=4, n, if(isprime(n), 3+2*(primepi(n)%2), 3+n-primepi(n)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 18 2020
STATUS
approved