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A068810
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Numbers n such that n and its 10's complement are both squares, i.e., n and 10^k - n (where k is the number of digits in n) are squares.
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1
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1, 9, 36, 64, 100, 324, 676, 900, 3600, 6400, 9216, 10000, 32400, 67600, 90000, 99856, 123904, 360000, 640000, 876096, 921600, 1000000, 3240000, 3968064, 6031936, 6760000, 9000000, 9985600, 12390400, 28901376, 36000000, 64000000
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OFFSET
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1,2
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COMMENTS
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Terms from V. P. Singh. If k in sequence so is k * 100^m. See A068075 for the smaller of the primitive pairs.
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LINKS
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EXAMPLE
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324 = 18^2 is a member as 1000 - 324 = 676 = 26^2.
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MATHEMATICA
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Select[Range[10^4]^2, IntegerQ[Sqrt[10^(IntegerLength[#]) - #]] &] (* Jayanta Basu, Aug 05 2013 *)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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