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%I #11 Jul 07 2014 00:23:00
%S 5,7,13,11,11,13,12,13,12,13,13,11,10,12,12,13,12,12,12,11,13,12,12,
%T 10,10,13,13,13,11,13,12,10,10,11,11,13,13,10,13,11,13,12,13,12,12,13,
%U 12,12,12,12,12,11,10,10,13,13,13,13,13,13,11,13,12,10,11,11,13
%N Number of n-digit non-leading-zero trimorphic numbers (m such that m^3 ends in m).
%C For n >= 3, I can show 8 <= a(n) <= 13 and I highly suspect that 10 <= a(n) <= 13 from empirical evidence.
%C If n >= 3, there are 15 integers 0 <= x < 10^n with x == 0,1 or -1 mod 5^n and
%C x == 0, 1, -1, 2^(n-1)-1 or 2^(n-1)+1 mod 2^n, and a(n) is the number of these
%C that are >= 10^(n-1). - _Robert Israel_, Jul 07 2014
%H Eric M. Schmidt, <a href="/A074755/b074755.txt">Table of n, a(n) for n = 1..1000</a>
%p f:= n ->
%p nops(select(`>=`,{seq(seq(chrem([a,b],[2^n,5^n]),a={0,1,2^(n-1)-1,2^(n-1)+1,-1}),b={0,1,-1})},10^(n-1))):
%p seq(f(n), n=1..100); # _Robert Israel_, Jul 07 2014
%Y Cf. A033819.
%K nonn,base
%O 1,1
%A _David W. Wilson_, Sep 28 2002
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