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A228381
Unabridged sub-Kaprekar numbers (A118936, but allowing powers of ten).
5
10, 11, 78, 100, 101, 287, 364, 1000, 1001, 1078, 1096, 1287, 1364, 10000, 10001, 11096, 18183, 100000, 100001, 118183, 336634, 1000000, 1000001, 1336634, 2727274, 10000000, 10000001, 12727274, 19138757, 23529412, 25974026, 97744361, 100000000, 100000001, 120879122, 123529412, 140017878, 165991904, 237762239, 288553552, 307692308, 333666334
OFFSET
1,1
COMMENTS
Square roots of A228103.
Excluding powers-of-ten and powers-of-ten-plus-one, what remains may be arranged into pairs (x,y), y>x, where y-x is a power of ten. The x terms correspond to A118938.
LINKS
EXAMPLE
10, because 10^2 = (10-0)^2
11, because 11^2 = (12-1)^2
78, because 78^2 = (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], Print[k]], {i, l-1}]] (* Hans Havermann, Aug 21 2013 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Hans Havermann, Aug 21 2013
STATUS
approved