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 A362551 #33 May 03 2023 09:11:39 %S A362551 0,10,1,20,11,2,30,21,31,12,3,40,22,41,13,51,61,32,23,4,50,42,52,14, %T A362551 71,81,33,5,91,6,101,43,62,72,53,24,15,60,34,82,25,92,111,44,7,121,8, %U A362551 131,63,73,35,9,141,16,151,70,161,54,83,26,102,17,112,45,93 %N A362551 a(0)=0. For each digit d in the sequence, append the smallest unused integer such that its last digit equals d. %C A362551 This sequence is a permutation of the nonnegative integers. %H A362551 Gavin Lupo, <a href="/A362551/b362551.txt">Table of n, a(n) for n = 0..10000</a> %H A362551 Gavin Lupo, <a href="/A362551/a362551.png">Image of the first 10000 terms.</a> %H A362551 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the nonnegative integers</a> %e A362551 a(0) = 0 %e A362551 a(1) = 10 (d=0 from a(0)=0, smallest integer other than 0 that ends with 0). %e A362551 a(2) = 1 (d=1 from a(1)=10, smallest integer that ends with a 1). %e A362551 a(3) = 20 (d=0 from a(1)=10, smallest integer other than 0 and 10 that ends with 0). %e A362551 a(4) = 11 (d=1 from a(2)=1, smallest integer other than 1 that ends with 1). %e A362551 a(5) = 2 (d=2 from a(3)=20, smallest integer that ends with 2). %e A362551 a(6) = 30 (d=0 from a(3)=20, smallest integer other than 0, 10, and 20 that ends with 0). %o A362551 (Python) %o A362551 from itertools import count, islice %o A362551 def agen(): # generator of terms %o A362551 s, lastd = "0", [(k for k in count(i, 10)) for i in range(10)] %o A362551 for n in count(0): %o A362551 an = next(lastd[int(s[0])]) %o A362551 s = s[1:] + str(an) %o A362551 yield an %o A362551 print(list(islice(agen(), 65))) # _Michael S. Branicky_, Apr 25 2023 %Y A362551 Cf. A106001, A362371. %K A362551 nonn,base,easy %O A362551 0,2 %A A362551 _Gavin Lupo_, Apr 24 2023