230081domain: NPropertiesPrimalityPrimeyesAppears in sequencesExpansion of e.g.f. exp(tanh(x)*exp(x)).at n=10A009268Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 2 5 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 2 5 6 or 7.at n=10A252507Prime numbersat n=20444