189419
domain: N
Appears in sequences
- a(1)=1. For n >= 2, a(n) = 2*a(n-1) + (number of composites among first n-1 terms of the sequence).at n=17A175104
- Strong Lucas pseudoprimes.at n=22A217255
- Extra strong Lucas pseudoprimes.at n=21A217719
- Numbers of the form p*q, p and q prime with q=2*p+3.at n=30A226754
- Composite numbers k such that Pell(k) == -1 (mod k).at n=14A319043