112751domain: NAppears in sequencesNumber of plane regions after drawing (in general position) a convex n-gon and all its diagonals.at n=40A027927Semiprimes of the form S(n) + T(n) where S(n) and T(n) are the n-th square and the n-th triangular numbers.at n=33A240914First row of spectral array W(3^(1/3)).at n=19A249179