a(n) = (A268922(n)^2 + 4)/5^n, n >= 0.

Terms

a(0) =4a(1) =1a(2) =5a(3) =1a(4) =109a(5) =1460a(6) =292a(7) =53476a(8) =124904a(9) =993169a(10) =5385572a(11) =43930532a(12) =239139524a(13) =777233593a(14) =789206948a(15) =2256445369a(16) =65340851012a(17) =661111023620a(18) =132222204724