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A383247 Positive integers that contain the digit 9, or an odd digit d immediately followed by a digit <= d.

%I A383247 #8 Apr 28 2025 12:19:59
%S A383247 9,10,11,19,29,30,31,32,33,39,49,50,51,52,53,54,55,59,69,70,71,72,73,
%T A383247 74,75,76,77,79,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,
%U A383247 105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,129,130,131,132,133
%N A383247 Positive integers that contain the digit 9, or an odd digit d immediately followed by a digit <= d.
%C A383247 Conjecture: these are the numbers missing from A342044.
%H A383247 Paolo Xausa, <a href="/A383247/b383247.txt">Table of n, a(n) for n = 1..10000</a>
%t A383247 A383247Q[k_] := MemberQ[#, 9] || MemberQ[Partition[#, 2, 1], {i_?OddQ, j_} /; j <= i] & [IntegerDigits[k]];
%t A383247 Select[Range[200], A383247Q]
%o A383247 (Python)
%o A383247 def ok(n):
%o A383247     s = str(n)
%o A383247     return "9" in s or any(d in "13579" and s[i]<=d for i, d in enumerate(s, 1) if i < len(s))
%o A383247 print([k for k in range(134) if ok(k)]) # _Michael S. Branicky_, Apr 28 2025
%Y A383247 Cf. A342044, A383248 (complement).
%Y A383247 Cf. A347298, A382464, A382623, A382937, A383061, A383245, A383249.
%K A383247 nonn,base,easy
%O A383247 1,1
%A A383247 _Paolo Xausa_, Apr 25 2025