a(0)=1, a(1)=4, a(n) = 10a(n-1) + a(n-2).

A109109

a(0)=1, a(1)=4, a(n) = 10a(n-1) + a(n-2).

Terms

    a(0) =1a(1) =4a(2) =41a(3) =414a(4) =4181a(5) =42224a(6) =426421a(7) =4306434a(8) =43490761a(9) =439214044a(10) =4435631201a(11) =44795526054a(12) =452390891741

External references