cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A289660 a(n) = A037276(n) - n.

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%I A289660 #14 Jul 27 2017 11:14:33
%S A289660 0,0,0,18,0,17,0,214,24,15,0,211,0,13,20,2206,0,215,0,205,16,189,0,
%T A289660 2199,30,187,306,199,0,205,0,22190,278,183,22,2197,0,181,274,2185,0,
%U A289660 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
%N A289660 a(n) = A037276(n) - n.
%C A289660 The fact that a(n)>0 if n is composite shows that (unlike A080670), A037276 has no nontrivial fixed points (nor any cycles).
%H A289660 Vincenzo Librandi, <a href="/A289660/b289660.txt">Table of n, a(n) for n = 1..1000</a>
%t A289660 FromDigits@Flatten@IntegerDigits[Table[#1,{#2}]&@@@FactorInteger@#]-#&/@Range@54 (* _Vincenzo Librandi_, Jul 25 2017 *)
%o A289660 (Python)
%o A289660 from sympy import factorint
%o A289660 def A289660(n):
%o A289660     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
%Y A289660 Cf. A037274, A037276, A080670.
%K A289660 nonn,base
%O A289660 1,4
%A A289660 _N. J. A. Sloane_, Jul 24 2017