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A212191
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Numbers whose squares are the sum of exactly three distinct powers of 2.
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4
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5, 7, 9, 10, 14, 17, 18, 20, 23, 28, 33, 34, 36, 40, 46, 56, 65, 66, 68, 72, 80, 92, 112, 129, 130, 132, 136, 144, 160, 184, 224, 257, 258, 260, 264, 272, 288, 320, 368, 448, 513, 514, 516, 520, 528, 544, 576, 640, 736, 896, 1025, 1026, 1028, 1032, 1040
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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COMMENTS
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The finite sequence 5, 7, 9, 10, 14, 17 arises in the following context: squarefree circular words over the ternary alphabet exist for all lengths n except for 5, 7, 9, 10, 14, 17. See Currie (2002), Shur (2010). - N. J. A. Sloane, May 04 2013
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LINKS
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FORMULA
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MATHEMATICA
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Select[Range[1, 1000], Total[IntegerDigits[#^2, 2]] == 3 &] (* T. D. Noe, Dec 07 2012 *)
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PROG
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(Haskell)
a212191 n = a212191_list !! (n-1)
a212191_list = map a000196 a212190_list
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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