A037920 - OEIS

%I #13 Jun 15 2022 15:54:34

%S 8,2,2,2,2,3,37,3,19,41,3,3,3,7,13,13,3,11123771,7,149,317,941,229,

%T 31219729,11,2084656339,3,347,911,118189,11,613,496501723,97,130517,

%U 917327,53,1832651281459,3,3,3,11,139,653,3863,5107

%N Trajectory of 8 under prime factor concatenation procedure.

%H Patrick De Geest, <a href="http://www.worldofnumbers.com/topic1.htm">Home Primes</a>

%o (Python)

%o from sympy import factorint

%o def iterate(n):

%o     flst, f = [n], sorted(factorint(n, multiple=True))

%o     while len(f) > 1:

%o         flst += f

%o         f = sorted(factorint(int("".join(map(str, f))), multiple=True))

%o     return flst

%o print(iterate(8)) # _Michael S. Branicky_, Aug 02 2021

%Y Cf. A037273, A006919.

%K fini,full,nonn,tabf,base

%O 0,1

%A _Jeff Burch_

%E Edited by _Charles R Greathouse IV_, Apr 30 2010