OFFSET
1,1
COMMENTS
Conjecture: all multiples of 3 are terms of this sequence.
LINKS
J. J. Camacho, Un Método Insospechado Para Encontrar Números Narcisistas (in Spanish)
EXAMPLE
For a(1) = 2:
2^3 = 8.
8^3 = 512.
5^3 + 1^3 + 2^3 = 134.
1^3 + 3^3 + 4^3 = 92.
9^3 + 2^3 = 737.
7^3 + 3^3 + 7^3 = 713.
7^3 + 1^3 + 3^3 = 371.
371 is a narcissistic number.
MATHEMATICA
(* A example with recurrence formula to test if the number belongs to this sequence *)
f[1] = 2;
f[n_] := Total[IntegerDigits[f[n - 1]]^3]
Table[Total[IntegerDigits[f[n]]^3], {n, 1, 10}]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
José de Jesús Camacho Medina, Feb 19 2021
STATUS
approved