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 A375216 #19 Jan 30 2025 16:27:47 %S A375216 1,1,1,1,1,1,2,1,1,1,2,1,3,2,3,1,1,1,2,1,3,2,3,1,4,4,5,2,6,3,4,1,1,1, %T A375216 2,1,3,2,3,1,4,4,5,2,6,3,4,1,5,7,8,5,9,6,7,2,10,8,9,3,10,4,5,1,1,1,2, %U A375216 1,3,2,3,1,4,4,5,2,6,3,4,1,5,7,8,5,9,6,7,2,10,8,9,3,10,4,5,1,6,11,12,11,13 %N A375216 n is the a(n)-th nonnegative integer having its multiset of binary digits. %H A375216 Alois P. Heinz, <a href="/A375216/b375216.txt">Table of n, a(n) for n = 0..65536</a> %F A375216 Ordinal transform of A073137. %e A375216 a(26) = 5 because 26 is the 5th nonnegative integer having its multiset of binary digits: 19 = 10011_2, 21 = 10101_2, 22 = 10110_2, 25 = 11001_2, 26 = 11010_2. %p A375216 p:= proc() 0 end: %p A375216 a:= proc(n) option remember; local t; %p A375216 t:= sort(Bits[Split](n)); p(t):= p(t)+1 %p A375216 end: %p A375216 seq(a(n), n=0..100); %Y A375216 Cf. A073137. %K A375216 nonn,look,base %O A375216 0,7 %A A375216 _Alois P. Heinz_, Jan 30 2025