42688
domain: N
Appears in sequences
- Numbers k such that 10*R_k + 7 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=16A056655
- Structured hexagonal diamond numbers (vertex structure 5).at n=31A100178
- a(n) is the largest number in row n of A380920.at n=28A380967
- Numbers k such that k - A224787(k) is a square.at n=24A386623