a(n) = 20*a(n-1) - 64*a(n-2) for n > 1; a(0) = 21, a(1) = 340.

A166914

a(n) = 20*a(n-1) - 64*a(n-2) for n > 1; a(0) = 21, a(1) = 340.

Terms

    a(0) =21a(1) =340a(2) =5456a(3) =87360a(4) =1398016a(5) =22369280a(6) =357912576a(7) =5726617600a(8) =91625947136

External references