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A119043
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Triangular numbers composed of digits {0,1,7}.
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2
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1, 10, 171, 1711, 1770, 10011, 111117701071, 17170010070077710, 101711101707777771, 701000700077010700, 1701111717707771071, 10010107100007777700, 101770070070071771070, 170107111111710707070, 1177170070777107111711, 70071707101001717077017171
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OFFSET
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1,2
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LINKS
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FORMULA
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MATHEMATICA
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Select[FromDigits/@Tuples[{0, 1, 7}, 12], OddQ[Sqrt[8#+1]]&] (* The program generates the first 8 terms of the sequence. *) (* Harvey P. Dale, Sep 06 2022 *)
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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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