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 A288528 #37 Aug 04 2022 15:03:51
%S A288528 1,2,3,4,5,6,7,8,9,12,21,23,32,34,43,45,54,56,65,67,76,78,87,89,98,
%T A288528 123,132,213,231,234,243,312,321,324,342,345,354,423,432,435,453,456,
%U A288528 465,534,543,546,564,567,576,645,654,657,675,678,687,756,765,768,786,789,798,867,876,879,897,978,987
%N A288528 Numbers with consecutive positive decimal digits after the digits are sorted.
%C A288528 The last term is a(462331) = 987654321.
%C A288528 Observation: the number of terms mentioned above is also A014145(9). Also the sum of the 9th row in the triangle A288777.
%C A288528 It appears that the number of terms with k digits in this sequence is also A288777(9,k), k>=1.
%H A288528 Michael S. Branicky, <a href="/A288528/b288528.txt">Table of n, a(n) for n = 1..10000</a>
%o A288528 (Python)
%o A288528 def ok(n): return "".join(sorted(str(n))) in "123456789"
%o A288528 print([k for k in range(999) if ok(k)]) # _Michael S. Branicky_, Aug 04 2022
%o A288528 (Python) # alternate for generating full sequence instantly
%o A288528 from itertools import permutations
%o A288528 frags = ["123456789"[i:j] for i in range(9) for j in range(i+1, 10)]
%o A288528 afull = sorted(int("".join(s)) for f in frags for s in permutations(f))
%o A288528 print(afull[:70]) # _Michael S. Branicky_, Aug 04 2022
%Y A288528 Subsequence of A215014.
%Y A288528 Supersequence of A138141.
%Y A288528 Cf. A014145, A033075, A288777.
%K A288528 nonn,base,easy,fini
%O A288528 1,2
%A A288528 _Omar E. Pol_, Jun 15 2017