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A046019 a(n) gives the number of different powers m^n for which the sum of the digits is equal to m. 11

%I #18 Sep 24 2018 16:53:13

%S 1,9,2,6,6,5,5,9,4,4,7,4,2,12,6,8,7,5,3,10,4,4,8,4,4,14,5,3,7,6,2,11,

%T 2,8,4,6,3,9,3,3,7,2,5,10,6,4,9,9,5,12,2,4,5,5,6,3,2,7,4,5,5,6,3,4,5,

%U 5,4,9,2,6,4,3,3,6,5,6,4,4,5,9,5,3,5,5,2,6,3,7,7,4,3,8,4,4,9,6,2,8,2,5,6,3

%N a(n) gives the number of different powers m^n for which the sum of the digits is equal to m.

%C Number of m >= 1 with m = sum of digits of m^n.

%H T. D. Noe, <a href="/A046019/b046019.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = 1 + A046471(n). - _T. D. Noe_, Nov 26 2008

%e a(7)=9 because:

%e 1^7=1

%e 18^7= 612220032 and 6+1+2+2+2+3+2=18

%e 27^7= 10460353203 and 1+4+6+3+5+3+2+3=27

%e 31^7= 27512614111 and 2+7+5+1+2+6+1+4+1+1+1=31

%e 34^7= 52523350144 and 5+2+5+2+3+3+5+1+4+4=34

%e 43^7= 271818611107 and 2+7+1+8+1+8+6+1+1+1+7=43

%e 53^7= 1174711139837 and 1+1+7+4+7+1+1+1+3+9+8+3+7=53

%e 58^7= 2207984167552 and 2+2+7+9+8+4+1+6+7+5+5+2=58

%e 68^7= 6722988818432 and 6+7+2+2+9+8+8+8+1+8+4+3+2=68

%e a(9)=4 because:

%e 1^9=1

%e 54^9=3904305912313344 and 3+9+4+3+5+9+1+2+3+1+3+3+4+4=54

%e 71^9=45848500718449031 and 4+5+8+4+8+5+7+1+8+4+4+9+3+1=71

%e 81^9=150094635296999121 and 1+5+9+4+6+3+5+2+9+6+9+9+9+1+2+1=81

%Y Cf. A124359, A152147 (table of m such that the sum of digits of m^n equals m)

%K nonn,base

%O 0,2

%A _David W. Wilson_

%E Examples provided by _Paolo P. Lava_, Oct 30 2006

%E Edited by _N. J. A. Sloane_ at the suggestion of _Andrew S. Plewe_, May 27 2007

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