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A289660 a(n) = A037276(n) - n. 2
0, 0, 0, 18, 0, 17, 0, 214, 24, 15, 0, 211, 0, 13, 20, 2206, 0, 215, 0, 205, 16, 189, 0, 2199, 30, 187, 306, 199, 0, 205, 0, 22190, 278, 183, 22, 2197, 0, 181, 274, 2185, 0, 195, 0, 2167, 290, 177, 0, 22175, 28, 205, 266, 2161, 0, 2279, 456, 2171, 262, 171, 0, 2175, 0, 169, 274, 222158, 448, 2245, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
COMMENTS
The fact that a(n)>0 if n is composite shows that (unlike A080670), A037276 has no nontrivial fixed points (nor any cycles).
LINKS
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
Sequence in context: A198810 A347532 A243911 * A096306 A335187 A231962
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Jul 24 2017
STATUS
approved

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Last modified April 14 10:04 EDT 2024. Contains 371657 sequences. (Running on oeis4.)