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A358701
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a(n) is the least number > 1 that needs n toggles in the trailing bits of its binary representation to become a square.
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1
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4, 5, 7, 14, 79, 831, 6495, 247614, 7361278, 743300286, 121387475838
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internal format)
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OFFSET
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0,1
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LINKS
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EXAMPLE
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a(0) = 4 = 100 in binary, 0 toggled bits needed;
a(1) = 5 = 101_2, 1 toggled bit -> 100_2 = 4;
a(2) = 7 = 111_2, 2 toggled bits -> 100_2 = 4;
a(3) = 14 = 1110_2, 3 toggled bits -> 1001_2 = 9;
a(4) = 79 = 1001111_2, 4 toggled bits -> 1000000_2 = 64;
a(5) = 831 = 1100111111_2, 5 toggled bits -> 1100010000_2 = 784 = 28^2.
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PROG
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(Go) // see linked program
(C#) // see linked program
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CROSSREFS
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KEYWORD
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nonn,base,hard,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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