112021

Appears in sequences

• Triangle T(n, k) = T(n-1, k) + T(n, k-1) + T(n-1, k-1) + T(n-2, k-1), with T(n, 1) = T(n, n) = 1, read by rows.at n=52A144447
• Templates for lunar primes in any base (version 3).at n=23A191420