This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A111427 #8 Nov 07 2018 20:09:23 %S A111427 0,0,0,0,0,1,2,24,1705,8646064,120879712950776, %T A111427 6984325661199418257711189170, %U A111427 2037364946117781220616409939151494028465982215442078400 %N A111427 Tribonacci(tetranacci(n)). %H A111427 Alois P. Heinz, <a href="/A111427/b111427.txt">Table of n, a(n) for n = 0..16</a> %F A111427 a(n) = A000073(A000078(n)). %p A111427 a:= n-> (<<0|1|0>, <0|0|1>, <1|1|1>>^((<<0|1|0|0>, %p A111427 <0|0|1|0>, <0|0|0|1>, <1|1|1|1>>^n)[1, 4]))[1, 3]: %p A111427 seq(a(n), n=0..12); # _Alois P. Heinz_, Nov 07 2018 %Y A111427 Cf. A000045, A000073, A000078, A007570. %K A111427 easy,nonn %O A111427 0,7 %A A111427 _Jonathan Vos Post_, Nov 13 2005