cp's OEIS Frontend

A226273 Number of distinct values u^v, where u and v are digits occurring in decimal representation of n.

%I A226273 #6 May 13 2015 13:41:49
%S A226273 1,1,1,1,1,1,1,1,1,1,2,1,3,3,3,3,3,3,3,3,3,3,1,4,3,4,4,4,4,4,3,3,4,1,
%T A226273 4,4,4,4,4,4,3,3,3,4,1,4,4,4,4,4,3,3,4,4,4,1,4,4,4,4,3,3,4,4,4,4,1,4,
%U A226273 4,4,3,3,4,4,4,4,4,1,4,4,3,3,4,4,4,4
%N A226273 Number of distinct values u^v, where u and v are digits occurring in decimal representation of n.
%C A226273 Row lengths in table A226272;
%C A226273 a(n) <= 61; A171102(1) = 1023456789 is the smallest number m such that a(m) = 61.
%C A226273 a(n) = 61 for almost all n, in the sense that the natural density of n such that a(n) < 61 is 0. - _Charles R Greathouse IV_, May 13 2015
%H A226273 Reinhard Zumkeller, <a href="/A226273/b226273.txt">Table of n, a(n) for n = 0..1000</a>
%e A226273 See A226272.
%o A226273 (Haskell)
%o A226273 a226273 = length . a226272_row :: Integer -> Int
%o A226273 (PARI) a(n)=if(n<9, return(1)); my(d=Set(digits(n)),v=List()); for(i=1,#d, for(j=1,#d, listput(v,d[i]^d[j]))); #Set(v) \\ _Charles R Greathouse IV_, May 13 2015
%K A226273 nonn,base
%O A226273 0,11
%A A226273 _Reinhard Zumkeller_, Jul 09 2013