A111435 - OEIS

%I #5 Aug 09 2018 20:18:14

%S 0,0,0,0,0,1,1,1,3,21,987,2178309,6557470319842,

%T 59425114757512643212875125,

%U 3016128079338728432528443992613633888712980904400501

%N a(n) = Fibonacci(hexanacci(n)).

%F a(n) = A000045(A001592(n)).

%e a(0) = Fibonacci(hexanacci(0)) = A000045(A001592(0)) = A000045(0) = 0.

%e a(1) = Fibonacci(hexanacci(1)) = A000045(A001592(1)) = A000045(0) = 0.

%e a(2) = Fibonacci(hexanacci(2)) = A000045(A001592(2)) = A000045(0) = 0.

%e a(3) = Fibonacci(hexanacci(3)) = A000045(A001592(3)) = A000045(0) = 0.

%e a(4) = Fibonacci(hexanacci(4)) = A000045(A001592(4)) = A000045(0) = 0.

%e a(5) = Fibonacci(hexanacci(5)) = A000045(A001592(5)) = A000045(1) = 1.

%e a(6) = Fibonacci(hexanacci(6)) = A000045(A001592(6)) = A000045(1) = 1.

%e a(7) = Fibonacci(hexanacci(7)) = A000045(A001592(7)) = A000045(2) = 1.

%e a(8) = A000045(A001592(8)) = A000045(4) = 3.

%e a(9) = A000045(A001592(9)) = A000045(8) = 21.

%e a(10) = A000045(A001592(10)) = A000045(16) = 987.

%e a(11) = A000045(A001592(11)) = A000045(32) = 2178309.

%e a(12) = A000045(A001592(12)) = A000045(63) = 6557470319842.

%p b:= proc(n) option remember; `if`(n<5, 0,

%p       `if`(n=5, 1, add(b(n-j), j=1..6)))

%p     end:

%p a:= n-> (<<0|1>, <1|1>>^b(n))[1,2]:

%p seq(a(n), n=0..14);  # _Alois P. Heinz_, Aug 09 2018

%Y Cf. A000045, A001592, A066178, A007570.

%K easy,nonn

%O 0,9

%A _Jonathan Vos Post_, Nov 13 2005