229625

Appears in sequences

• a(n) is the number of 2 X 2 matrices with entries in {1, ..., n} that are not the product of two 2 X 2 positive integer matrices.at n=23A260550
• a(0) = 33. a(n) = 3*a(n-1) + 2*n + 1 for n >= 1.at n=8A370481