147971domain: NAppears in sequencesNumber of n X 3 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.at n=19A223765a(n) = numerator of (1/n^3)*(-1/(n+1) + 16/(n+2) + 3/(4*(2*n+1)) - 81/(4*(2*n+3))), term of a BBP-type series representation of zeta(3) by V. Adamchik and S. Wagon.at n=26A256323