Generalized Fibonacci numbers: a(n) = a(n-1) + 8*a(n-2).

Terms

a(0) =1a(1) =1a(2) =9a(3) =17a(4) =89a(5) =225a(6) =937a(7) =2737a(8) =10233a(9) =32129a(10) =113993a(11) =371025a(12) =1282969a(13) =4251169a(14) =14514921a(15) =48524273a(16) =164643641a(17) =552837825a(18) =1869986953a(19) =6292689553a(20) =21252585177a(21) =71594101601a(22) =241614783017a(23) =814367595825