OFFSET
1,4
COMMENTS
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
FromDigits@Flatten@IntegerDigits[Table[#1, {#2}]&@@@FactorInteger@#]-#&/@Range@54 (* Vincenzo Librandi, Jul 25 2017 *)
PROG
(Python)
from sympy import factorint
def A289660(n):
return 0 if n == 1 else int(''.join(map(lambda x: str(x[0])*x[1], sorted(factorint(n).items())))) - n # Chai Wah Wu, Jul 25 2017
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Jul 24 2017
STATUS
approved