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A212192
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Triangular numbers that are the sum of exactly three distinct powers of 2.
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3
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OFFSET
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1,1
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COMMENTS
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Triangular numbers with exactly three ones in their binary representation: A000120(a(n)) = 3; triangular numbers in A014311; no more terms less than A014311(1000000) = 6129982174881536975083663305496791903885182827960991744.
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LINKS
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MATHEMATICA
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Select[Accumulate[Range[60]], Total[IntegerDigits[#, 2]]==3&] (* Harvey P. Dale, Mar 11 2023 *)
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PROG
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(Haskell)
a212192 n = a212192_list !! (n-1)
a212192_list = filter ((== 1) . a010054) a014311_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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