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%I #25 Jan 02 2023 12:30:49
%S 100,121,6084,10000,10201,82369,132496,1000000,1002001,1162084,
%T 1201216,1656369,1860496,100000000,100020001,123121216,330621489,
%U 10000000000,10000200001,13967221489,113322449956,1000000000000,1000002000001,1786590449956,7438023471076,100000000000000,100000020000001,161983503471076,366292019505049,553633229065744,674650026648676,9553960107298321,10000000000000000,10000000200000001
%N Numbers n whose base-10 digits can be split into two parts, q and r, with n = (q-r)^2.
%C q*10^m+r = (q-r)^2; q,m>0; 0<=r<10^m = A228381^2 - _Hans Havermann_, Aug 21 2013
%H Hans Havermann, <a href="/A228103/b228103.txt">Table of n, a(n) for n = 1..1016</a>
%H Daniel Joyce, Robert Israel and Lars Blomberg, <a href="http://list.seqfan.eu/oldermail/seqfan/2013-August/011546.html">Can more of these terms be found?</a>
%H J. B. Wood, <a href="http://mathforum.org/kb/message.jspa?messageID=9188302">Quick Solution to Puzzle?</a>
%e 100 = (10-0)^2.
%e 121 = (12-1)^2.
%e 6084 = (6-084)^2.
%t k=3; While[k<10^8, k++; s=k^2; d=IntegerDigits[s]; l=Length[d]; Do[a=FromDigits[Take[d,{1,i}]]; b=FromDigits[Take[d,{i+1,l}]]; If[k==Abs[a-b], w=ToString[s]; Print[StringTake[w,{1,i}], "'", StringTake[w,{i+1,l}]]], {i,l-1}]] (* _Hans Havermann_, Aug 10 2013, Aug 20 2013 *)
%Y Cf. A102766, A118936, A228381.
%K nonn,base
%O 1,1
%A _Hans Havermann_, Aug 10 2013
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