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 A382623 #9 Apr 08 2025 23:12:55
%S A382623 12,14,16,18,22,24,26,28,34,36,38,44,46,48,56,58,66,68,78,88,100,102,
%T A382623 104,106,108,112,114,116,118,120,121,122,123,124,125,126,127,128,129,
%U A382623 134,136,138,140,141,142,143,144,145,146,147,148,149,156,158,160,161,162,163
%N A382623 Positive integers that contain an even digit d immediately preceded by a digit <= d.
%C A382623 Conjecture: these are the numbers missing from A382621.
%H A382623 Paolo Xausa, <a href="/A382623/b382623.txt">Table of n, a(n) for n = 1..10000</a>
%t A382623 A382623Q[k_] := MemberQ[Partition[IntegerDigits[k], 2, 1], {i_, j_?EvenQ} /; i <= j];
%t A382623 Select[Range[200], A382623Q]
%o A382623 (Python)
%o A382623 def ok(n):
%o A382623 s = str(n)
%o A382623 return any(s[i+1] >= s[i] for i in range(len(s)-1) if s[i+1] in "02468")
%o A382623 print([k for k in range(1, 164) if ok(k)]) # _Michael S. Branicky_, Apr 03 2025
%Y A382623 Cf. A347298, A382464, A382621, A382624 (complement).
%K A382623 nonn,base,easy
%O A382623 1,1
%A A382623 _Paolo Xausa_, Apr 01 2025