A111427 Tribonacci(tetranacci(n)).

0, 0, 0, 0, 0, 1, 2, 24, 1705, 8646064, 120879712950776, 6984325661199418257711189170, 2037364946117781220616409939151494028465982215442078400

Offset: 0

Author

Jonathan Vos Post, Nov 13 2005

Keywords

• easy
• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..16

Crossrefs

Cf. A000045, A000073, A000078, A007570.

Programs

Maple

a:= n-> (<<0|1|0>, <0|0|1>, <1|1|1>>^((<<0|1|0|0>,
        <0|0|1|0>, <0|0|0|1>, <1|1|1|1>>^n)[1, 4]))[1, 3]:
seq(a(n), n=0..12);  # Alois P. Heinz, Nov 07 2018

Formula

a(n) = A000073(A000078(n)).