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 A338835 #12 Nov 14 2020 01:50:33
%S A338835 0,1,2,4,3,5,6,12,8,18,14,24,7,13,10,20,19,26,9,16,15,25,22,28,11,21,
%T A338835 17,27,23,29,30,60,36,90,66,120,32,62,61,96,92,150,42,91,72,126,122,
%U A338835 180,68,121,102,156,152,186,98,151,132,182,181,192,31,38,37,67
%N A338835 a(n) is the greatest number not yet in the sequence with the same number of digits and the same sum of digits as n in primorial base.
%C A338835 This sequence is a self-inverse permutation of the nonnegative integers.
%H A338835 Rémy Sigrist, <a href="/A338835/b338835.txt">Table of n, a(n) for n = 0..2309</a>
%H A338835 Rémy Sigrist, <a href="/A338835/a338835.png">Colored scatterplot of the first 2*3*5*7*11*13 terms</a> (where the color is function of A276150(n))
%H A338835 Rémy Sigrist, <a href="/A338835/a338835.gp.txt">PARI program for A338835</a>
%H A338835 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F A338835 A235224(a(n)) = A235224(n).
%F A338835 A276150(a(n)) = A276150(n).
%e A338835 For n = 8:
%e A338835 - the numbers with 3 digits and sum of digits 2 in primorial base are: 7 ("101"), 8 ("110") and 12 ("200"),
%e A338835 - so a(7) = 12,
%e A338835 a(8) = 8,
%e A338835 a(12) = 7.
%o A338835 (PARI) See Links section.
%Y A338835 Cf. A235224, A276150, A333658, A338829 (decimal analog), A338834 (factorial base analog).
%K A338835 nonn,base
%O A338835 0,3
%A A338835 _Rémy Sigrist_, Nov 11 2020