This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A382465 #14 Apr 30 2025 11:08:58
%S A382465 1,2,3,4,5,6,7,8,9,11,12,13,14,15,16,17,18,19,21,23,24,25,26,27,28,29,
%T A382465 31,33,34,35,36,37,38,39,41,43,45,46,47,48,49,51,53,55,56,57,58,59,61,
%U A382465 63,65,67,68,69,71,73,75,77,78,79,81,83,85,87,89,91,93,95,97,99
%N A382465 Positive integers such that every even digit except the first is immediately preceded by a smaller digit.
%C A382465 Conjecture: these are the terms of A382462, sorted.
%H A382465 Paolo Xausa, <a href="/A382465/b382465.txt">Table of n, a(n) for n = 1..10000</a>
%t A382465 A382465Q[k_] := FreeQ[Partition[IntegerDigits[k], 2, 1], {i_, j_?EvenQ} /; i >= j];
%t A382465 Select[Range[100], A382465Q]
%o A382465 (Python)
%o A382465 def ok(n):
%o A382465 s = str(n)
%o A382465 return n and all(d not in "02468" or s[i-1]<d for i, d in enumerate(s) if i > 0)
%o A382465 print([k for k in range(100) if ok(k)]) # _Michael S. Branicky_, Apr 30 2025
%Y A382465 Cf. A382462, A382464 (complement).
%Y A382465 Cf. A377912, A382624, A382938, A383062, A383246, A383248, A383250, A383501.
%K A382465 nonn,base,easy
%O A382465 1,2
%A A382465 _Paolo Xausa_, Mar 28 2025