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A119208
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Triangular numbers composed of digits {4,5,9}.
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2
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45, 55, 595, 5995, 49455, 55945, 594595, 5559445, 555594445, 9955945495, 55555944445, 95444955595, 5555559444445, 9545454599955, 499594959455595, 549999555454495, 555555594444445, 55555555944444445, 5555555559444444445, 5999995494459499455
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OFFSET
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1,1
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LINKS
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FORMULA
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MATHEMATICA
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Select[Flatten[Table[FromDigits/@Tuples[{4, 5, 9}, n], {n, 17}]], OddQ[ Sqrt[ 8#+1]]&] (* The program will take a long time to run. *) (* Harvey P. Dale, May 23 2021 *)
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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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