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A131760
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Numbers n such that n multiplied by its reverse yields a fourth power.
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1
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1, 4, 9, 121, 484, 676, 2178, 8712, 10000, 10201, 12321, 14641, 40000, 40804, 44944, 69696, 90000, 94249, 698896, 1002001, 1210000, 1234321, 4008004, 4840000, 5221225, 6760000, 6948496, 21780000, 87120000, 100000000, 100020001
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OFFSET
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1,2
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COMMENTS
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This sequence contains palindromic squares and palindromic squares with trailing zeros. Are 2178 and 8721 the only non-palindromic reversible pair in this sequence without trailing zeros?
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LINKS
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EXAMPLE
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2178 = 2*9*121 and 8712 = 8*9*121, 2718*8712 = (2*3*11)^4.
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MATHEMATICA
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Select[Range[1000000], IntegerQ[(#*FromDigits[Reverse[IntegerDigits[ # ]]])^(1/4)] &]
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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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