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A119170
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Triangular numbers composed of digits {2,5,9}.
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2
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55, 595, 5995, 255255, 292995, 299925, 25952229225, 99292929555225, 55955525255559595, 555959229929999252295, 925952955522559552259925, 5299552922255552929595999295, 5995959559225555222929295255522595295, 9925559955529295222599225259529552225
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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a(n) == 5 (mod 10) for all n. - Chai Wah Wu, Nov 30 2018
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MATHEMATICA
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Flatten[Table[Select[FromDigits /@ Tuples[{2, 5, 9}, n], IntegerQ[(Sqrt[8 # + 1] - 1)/2] &], {n, 11}]] (* Amiram Eldar, Nov 30 2018 *)
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CROSSREFS
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KEYWORD
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nonn,base,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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