a(n) = ((1+sqrt(5))*(4+sqrt(5))^n + (1-sqrt(5))*(4-sqrt(5))^n)/2.
A162769
a(n) = ((1+sqrt(5))*(4+sqrt(5))^n + (1-sqrt(5))*(4-sqrt(5))^n)/2.
Terms
- a(0) =1a(1) =9a(2) =61a(3) =389a(4) =2441a(5) =15249a(6) =95141a(7) =593389a(8) =3700561a(9) =23077209a(10) =143911501a(11) =897442709a(12) =5596515161a(13) =34900251489a(14) =217640345141
External references
- oeis: A162769