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 A323462 #27 Jan 09 2025 13:05:08 %S A323462 1,1,3,2,5,3,7,4,9,5,11,6,13,7,15,8,17,9,19,10,11,11,13,12,15,13,17, %T A323462 14,19,15,31,16,33,17,35,18,37,19,39,20,21,21,23,22,25,23,27,24,29,25, %U A323462 51,26,53,27,55,28,57,29,59,30,31,31,33,32,35,33,37,34,39,35,71,36,73,37,75,38,77,39,79,40,41 %N A323462 Smallest number that can be obtained from the "Choix de Bruxelles", version 2 (A323460) operation applied to n. %C A323462 Smallest element in row n of irregular triangle in A323460. %C A323462 Theorem: Let the decimal expansion of n be d_1 d_2 ... d_k. (i) If there is a substring d_r ... d_s which starts with d_r = 1 and ends with an even digit d_s = e, take that string which starts with the leftmost 1 and ends with the rightmost even digit, and halve it. (ii) Otherwise, if there is an even digit e, take the substring from d_1 to the rightmost such e and halve it. (iii) Otherwise, all d_i are odd, and a(n) = n. %H A323462 Eric Angelini, Lars Blomberg, Charlie Neder, Remy Sigrist, and N. J. A. Sloane, <a href="http://arxiv.org/abs/1902.01444">"Choix de Bruxelles": A New Operation on Positive Integers</a>, arXiv:1902.01444, Feb 2019; Fib. Quart. 57:3 (2019), 195-200. %H A323462 Eric Angelini, Lars Blomberg, Charlie Neder, Remy Sigrist, and N. J. A. Sloane,, <a href="/A307635/a307635.pdf">"Choix de Bruxelles": A New Operation on Positive Integers</a>, Local copy. %e A323462 From 23 we can reach any of 13, 43, 26, 46, and the smallest of these is a(23) = 13. %Y A323462 Cf. A323286, A323460, A323288. %K A323462 nonn,base %O A323462 1,3 %A A323462 _N. J. A. Sloane_, Jan 23 2019