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 A342117 #11 Mar 01 2021 02:12:45 %S A342117 0,1,5,3,4,2,27,24,21,9,29,18,17,28,26,16,15,12,11,25,23,8,22,20,7,19, %T A342117 14,6,13,10,189,147,144,180,207,204,111,159,150,39,201,129,198,197, %U A342117 196,120,195,108,192,191,188,99,209,187,186,184,183,90,208,182,77 %N A342117 Lexicographically latest sequence of distinct nonnegative integers such that the multisets of frequencies of digits in the primorial base representations of n and of a(n) are the same. %C A342117 This sequence is a self-inverse permutation of the nonnegative integers. %H A342117 Rémy Sigrist, <a href="/A342117/b342117.txt">Table of n, a(n) for n = 0..2309</a> %H A342117 Rémy Sigrist, <a href="/A342117/a342117_1.png">Colored scatterplot of the first 2*3*5*7*11*13 terms</a> (where the color is function of the multiset of frequencies of n) %H A342117 Rémy Sigrist, <a href="/A342117/a342117.gp.txt">PARI program for A342117</a> %H A342117 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a> %H A342117 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A342117 a(n) < A002110(k) for any n < A002110(k). %e A342117 The first terms, in decimal and in primorial base, alongside the corresponding multisets of frequencies (ignoring 0's), are: %e A342117 n a(n) prim(n) prim(a(n)) freq(n) %e A342117 -- ---- ------- ---------- ------------ %e A342117 0 0 0 0 () %e A342117 1 1 1 1 (1) %e A342117 2 5 10 21 (1, 1) %e A342117 3 3 11 11 (2) %e A342117 4 4 20 20 (1, 1) %e A342117 5 2 21 10 (1, 1) %e A342117 6 27 100 411 (1, 2) %e A342117 7 24 101 400 (1, 2) %e A342117 8 21 110 311 (1, 2) %e A342117 9 9 111 111 (3) %e A342117 10 29 120 421 (1, 1, 1) %e A342117 11 18 121 300 (1, 2) %e A342117 12 17 200 221 (1, 2) %o A342117 (PARI) See Links section. %Y A342117 See A342102 for similar sequences. %Y A342117 Cf. A002110, A235168. %K A342117 nonn,base %O A342117 0,3 %A A342117 _Rémy Sigrist_, Feb 28 2021