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A098949
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Numbers where 9 is the only odd decimal digit.
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2
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9, 29, 49, 69, 89, 90, 92, 94, 96, 98, 99, 209, 229, 249, 269, 289, 290, 292, 294, 296, 298, 299, 409, 429, 449, 469, 489, 490, 492, 494, 496, 498, 499, 609, 629, 649, 669, 689, 690, 692, 694, 696, 698, 699, 809, 829, 849, 869, 889, 890, 892, 894, 896, 898
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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COMMENTS
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This is a regular language in base 10. - Charles R Greathouse IV, Oct 05 2011
The number of terms of this sequence that are smaller than 10^n is n*5^(n-1). - Stefan Steinerberger, Jun 06 2006
Any number of 9s is permitted. - Harvey P. Dale, May 07 2019
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LINKS
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Harvey P. Dale, Table of n, a(n) for n = 1..2000
Index entries for 10-automatic sequences
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MATHEMATICA
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Select[Range[1000], DigitCount[ # ][[1]] == 0 && DigitCount[ # ][[3]] == 0 && DigitCount[ # ][[5]] == 0 && DigitCount[ # ][[7]] == 0 && DigitCount[ # ][[9]] >0 &] (* Stefan Steinerberger, Jun 06 2006; corrected by Harvey P. Dale, May 07 2019 *)
Select[Range[1000], Union[Select[IntegerDigits[#], OddQ]]=={9}&] (* Harvey P. Dale, May 07 2019 *)
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PROG
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(Perl) for (0..1000) {
print "$_, " if (/^[024689]*9[024689]*$/)
} # Charles R Greathouse IV, Oct 05 2011
(Python)
def ok(n): return set(str(n)) & set("13579") == set("9")
print(list(filter(ok, range(899)))) # Michael S. Branicky, Sep 29 2021
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CROSSREFS
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Sequence in context: A032700 A322946 A350963 * A031296 A146869 A129397
Adjacent sequences: A098946 A098947 A098948 * A098950 A098951 A098952
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KEYWORD
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base,easy,nonn
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AUTHOR
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Eric Angelini, Oct 21 2004
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EXTENSIONS
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More terms from Stefan Steinerberger, Jun 06 2006
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STATUS
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approved
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