a(n) = ((4 + sqrt(18))*(4 + sqrt(8))^n + (4 - sqrt(18))*(4 - sqrt(8))^n)/8 .
A164591
a(n) = ((4 + sqrt(18))*(4 + sqrt(8))^n + (4 - sqrt(18))*(4 - sqrt(8))^n)/8 .
Terms
- a(0) =1a(1) =7a(2) =48a(3) =328a(4) =2240a(5) =15296a(6) =104448a(7) =713216a(8) =4870144a(9) =33255424a(10) =227082240a(11) =1550614528a(12) =10588258304a(13) =72301150208a(14) =493703135232
External references
- oeis: A164591