46397domain: NAppears in sequencesa(n) = b(n) + d(n), where b(n) = (n-th Fibonacci number > 1) and d(n) = (n-th non-Fibonacci number).at n=21A023483a(n) = (2*n - 1)*(7*n^2 - 7*n + 3)/3.at n=21A063494Composite squarefree numbers n such that p(i)-3 divides n+3, where p(i) are the prime factors of n.at n=6A225703