a(n) = 4*a(n-1)+20*a(n-2) for n>=3, a(0)=1, a(1)=4, a(2)=32.

A133642

a(n) = 4*a(n-1)+20*a(n-2) for n>=3, a(0)=1, a(1)=4, a(2)=32.

Terms

    a(0) =1a(1) =4a(2) =32a(3) =208a(4) =1472a(5) =10048a(6) =69632a(7) =479488a(8) =3310592a(9) =22832128a(10) =157540352a(11) =1086803968a(12) =7498022912a(13) =51728171008a(14) =356873142272

External references