OFFSET
1,1
COMMENTS
q*10^m+r = (q-r)^2; q,m>0; 0<=r<10^m = A228381^2 - Hans Havermann, Aug 21 2013
LINKS
Hans Havermann, Table of n, a(n) for n = 1..1016
Daniel Joyce, Robert Israel and Lars Blomberg, Can more of these terms be found?
J. B. Wood, Quick Solution to Puzzle?
EXAMPLE
100 = (10-0)^2.
121 = (12-1)^2.
6084 = (6-084)^2.
MATHEMATICA
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 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Hans Havermann, Aug 10 2013
STATUS
approved