A262361 a(n) = L(L(L(n))), where L(n) are Lucas numbers A000032.

4, 1, 7, 29, 1149851, 387739824812222466915538827541705412334749

Offset: 0

Author

Alois P. Heinz, Nov 09 2016

Keywords

• nonn

Comments

a(6) = 3393011755..4322744978 has 1208 decimal digits and a(7) = 4437405101..8830136999 has 240305 decimal digits.

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..5

Crossrefs

Cf. A000032, A005371, A058051.

Programs

Maple

L:= n-> (<<0|1>, <1|1>>^n. <<2, 1>>)[1$2]:
a:= n-> L(L(L(n))):
seq(a(n), n=0..5);

Mathematica

A262361 = Nest[LucasL, #, 3] &; Array[A262361, 6, 0] (* JungHwan Min, Nov 09 2016 *)

Python

from sympy import lucas as L
def a(n):  return L(L(L(n)))
print([a(n) for n in range(6)]) # Michael S. Branicky, Apr 01 2021