182300

Appears in sequences

• a(n) = Sum_{k=0..floor(n/4)} (-1)^k * binomial(n+3,4*k+3) * Catalan(k).at n=17A360050
• a(n) is the number of 2 X 2 matrices with elements 1..n where at least one row, at least one column and at least one of the two diagonals is strictly increasing.at n=25A391092