A113009 - OEIS

%I #11 Feb 28 2019 18:52:26

%S 0,1,2,3,4,5,6,7,8,9,1,4,9,16,25,36,49,64,81,100,4,9,16,25,36,49,64,

%T 81,100,121,9,16,25,36,49,64,81,100,121,144,16,25,36,49,64,81,100,121,

%U 144,169,25,36,49,64,81,100,121,144,169,196,36,49,64,81,100,121,144,169,196

%N {Sum of the digits of n} raised to the power {number of digits of n}.

%C Fixed points are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 81, 5832. Are there any others?

%C Fixed points include: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 81, 512, 2401. There are no other fixed points less than 10^1000. - _Chai Wah Wu_, Feb 28 2019

%F a(ijk...)[m digits ijk...]=(i+j+k)^m

%e a(9)=9^1=9

%e a(19)=(1+9)^2=100

%e a(101)=(1+0+1)^3=8

%t Join[{0},Table[Total[IntegerDigits[n]]^IntegerLength[n],{n,100}]] (* _Harvey P. Dale_, Nov 09 2014 *)

%o (Python)

%o def A113009(n):

%o     return sum(int(d) for d in str(n))**len(str(n)) # _Chai Wah Wu_, Feb 28 2019

%Y Cf. A101337.

%K base,easy,nonn

%O 0,3

%A _Alexandre Wajnberg_, Jan 03 2006