a(n) = 5*a(n-1) + 5*a(n-2), n > 2, a(0)=1, a(1)=4, a(2)=24.

A155119

a(n) = 5*a(n-1) + 5*a(n-2), n > 2, a(0)=1, a(1)=4, a(2)=24.

Terms

    a(0) =1a(1) =4a(2) =24a(3) =140a(4) =820a(5) =4800a(6) =28100a(7) =164500a(8) =963000a(9) =5637500a(10) =33002500a(11) =193200000a(12) =1131012500a(13) =6621062500a(14) =38760375000a(15) =226907187500

External references