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A038687 Concatenate i >= 1 and j >= 1, then sort.

%I A038687 #17 Jul 08 2025 22:25:16
%S A038687 11,12,13,14,15,16,17,18,19,21,22,23,24,25,26,27,28,29,31,32,33,34,35,
%T A038687 36,37,38,39,41,42,43,44,45,46,47,48,49,51,52,53,54,55,56,57,58,59,61,
%U A038687 62,63,64,65,66,67,68,69,71,72,73,74,75,76,77,78,79,81,82,83,84,85,86,87,88,89,91,92,93,94,95,96,97,98,99,101,102,103,104,105,106,107,108,109,110,111,112
%N A038687 Concatenate i >= 1 and j >= 1, then sort.
%C A038687 Numbers with at least two nonzero decimal digits. - _Charles R Greathouse IV_, Jan 13 2015
%H A038687 Harvey P. Dale, <a href="/A038687/b038687.txt">Table of n, a(n) for n = 1..1000</a>
%F A038687 a(n) = n + O(log n). - _Charles R Greathouse IV_, Jan 13 2015
%p A038687 isA038687 := proc(n)
%p A038687     local nzdigs,d ;
%p A038687     nzdigs := 0 ;
%p A038687     for d in convert(n,base,10) do
%p A038687         if d > 0 then
%p A038687             nzdigs := nzdigs+1 ;
%p A038687         end if ;
%p A038687     end do:
%p A038687     simplify(nzdigs>=2 ) ;
%p A038687 end proc:
%p A038687 for n from 1 to 120 do
%p A038687     if isA038687(n) then
%p A038687         printf("%d,",n) ;
%p A038687     end if;
%p A038687 end do: # _R. J. Mathar_, May 25 2023
%t A038687 Select[Range[150],Total[Most[DigitCount[#]]]>1&] (* _Harvey P. Dale_, Dec 15 2023 *)
%o A038687 (PARI) is(n)=n/=10^valuation(n,10); n>9 \\ _Charles R Greathouse IV_, Jan 13 2015
%K A038687 nonn,base,easy
%O A038687 1,1
%A A038687 _N. J. A. Sloane_