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 A262361 #28 Apr 01 2021 14:54:08 %S A262361 4,1,7,29,1149851,387739824812222466915538827541705412334749 %N A262361 a(n) = L(L(L(n))), where L(n) are Lucas numbers A000032. %C A262361 a(6) = 3393011755..4322744978 has 1208 decimal digits and a(7) = 4437405101..8830136999 has 240305 decimal digits. %H A262361 Alois P. Heinz, <a href="/A262361/b262361.txt">Table of n, a(n) for n = 0..5</a> %p A262361 L:= n-> (<<0|1>, <1|1>>^n. <<2, 1>>)[1$2]: %p A262361 a:= n-> L(L(L(n))): %p A262361 seq(a(n), n=0..5); %t A262361 A262361 = Nest[LucasL, #, 3] &; Array[A262361, 6, 0] (* _JungHwan Min_, Nov 09 2016 *) %o A262361 (Python) %o A262361 from sympy import lucas as L %o A262361 def a(n): return L(L(L(n))) %o A262361 print([a(n) for n in range(6)]) # _Michael S. Branicky_, Apr 01 2021 %Y A262361 Cf. A000032, A005371, A058051. %K A262361 nonn %O A262361 0,1 %A A262361 _Alois P. Heinz_, Nov 09 2016