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A117993
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Heptagonal numbers with only odd digits.
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1
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1, 7, 55, 1177, 3553, 9517, 11799, 13579, 17935, 31753, 71995, 93799, 97713, 117397, 135373, 371911, 377719, 599515, 733597, 777573, 1131313, 1331155, 1371591, 1555119, 3391315, 3731377, 3979717, 5131573, 7137715, 7333353, 9193933, 13755771, 13979515
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OFFSET
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1,2
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LINKS
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MATHEMATICA
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Select[Table[n (5n-3)/2, {n, 4000}], AllTrue[IntegerDigits[#], OddQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 28 2015 *)
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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Luc Stevens (lms022(AT)yahoo.com), May 03 2006
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EXTENSIONS
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STATUS
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approved
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