a(n) = 5*a(n-1) + a(n-2) - 5*a(n-3), for n>4, with a(1)=1, a(2)=0, a(3)=4, a(4)=16.

A123010

a(n) = 5*a(n-1) + a(n-2) - 5*a(n-3), for n>4, with a(1)=1, a(2)=0, a(3)=4, a(4)=16.

Terms

    a(0) =1a(1) =0a(2) =4a(3) =16a(4) =84a(5) =416a(6) =2084a(7) =10416a(8) =52084a(9) =260416a(10) =1302084a(11) =6510416a(12) =32552084a(13) =162760416a(14) =813802084a(15) =4069010416a(16) =20345052084a(17) =101725260416a(18) =508626302084

External references