42897

Appears in sequences

• a(1) = 3; a(n) = smallest number such that the forward as well as the reverse n-th partial concatenation is a prime for n>1. (Reverse concatenation is taken term-wise and not digit-wise).at n=36A083993
• Number of nX5 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=8A302306