91230

Appears in sequences

• Number of n X n arrays of squares of integers with every (n-1)X(n-1) subblock summing to 4 and every element equal to at least one neighbor.at n=10A146090
• Number of nonempty subsets of {1, 2, ..., n} with <=10 pairwise coprime elements.at n=35A187271
• Numbers n such that 10^n + 9^(n+1) is prime.at n=23A275783