a(n) = a(n-1) * (11*a(n-1) - a(n-2)) / (a(n-1) + 4*a(n-2)), with a(0) = a(1) = 1.
A172511
a(n) = a(n-1) * (11*a(n-1) - a(n-2)) / (a(n-1) + 4*a(n-2)), with a(0) = a(1) = 1.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =7a(4) =35a(5) =210a(6) =1365a(7) =9165a(8) =62322a(9) =425867a(10) =2915551a(11) =19974626a(12) =136884937a(13) =938162617a(14) =6430103330a(15) =44072167855a(16) =302074043195
External references
- oeis: A172511