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Search: id:A068810
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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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+0
2
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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
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Terms by 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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EXAMPLE
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324=18^2 is a member as 1000-324 = 676 = 26^2.
Select[ Range[10^4], IntegerQ[ Sqrt[ 10^Floor[ Log[10, #^2] + 1] - #^2]] &]^2
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CROSSREFS
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Cf. A068075.
Adjacent sequences: A068807 A068808 A068809 this_sequence A068811 A068812 A068813
Sequence in context: A137628 A020297 A143224 this_sequence A077115 A073946 A016766
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KEYWORD
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nonn,base
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 07 2002
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EXTENSIONS
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Edited and extended by Robert G. Wilson v), Mar 20 2002
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