OFFSET
1,1
COMMENTS
FORMULA
A335885(a(n)) = 2.
PROG
(PARI)
isA000668(n) = (isprime(n)&&!bitand(n, 1+n));
isA019434(n) = ((n>2)&&isprime(n)&&!bitand(n-2, n-1));
isA336115(n) = if(9==n, 1, if((2!=omega(n))||(2!=bigomega(n)), 0, my(ps=factor(n)[, 1]); (isA019434(ps[1])&&isA000668(ps[2]))||(isA019434(ps[2])&&isA000668(ps[1])))); \\ Antti Karttunen, Jul 11 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 09 2020
EXTENSIONS
Missing terms and more terms added by Jinyuan Wang, Jul 11 2020
STATUS
approved