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 A378876 #25 Jan 18 2025 09:36:25 %S A378876 1,1,2,1,4,1,3,1,3,3,2,2,2,3,6,1,2,3,3,6,3,4,2,2,3,5,1,2,3,5,5,2,2,3, %T A378876 6,5,2,3,5,5,5,3,5,5,6,3,5,9,1,2,3,4,4,2,3,5,4,2,3,5,5,6,6,2,2,3,5,8, %U A378876 1,2,3,4,5,5,3,5,5,6,7,1,2,3,4,5,6,3,5,5 %N A378876 a(1)=1; thereafter a(n) is the smallest k for which the subsequence a(n-k..n-1) has a distinct multiset from that of any other subsequence of the sequence thus far. %C A378876 In other words, a(n) is the length of the shortest subsequence ending at a(n-1) which has a unique multiset among all multisets of subsequences of the sequence thus far. Alternatively, this is (the length of the longest subsequence ending at a(n-1) whose multiset has occurred before as that of another subsequence) plus 1. %e A378876 a(15) = 6 because the length-6 subsequence a(9..14) = 3,3,2,2,2,3 has the shortest unique multiset, which does not occur elsewhere as the multiset of any other subsequence in the sequence thus far. No shorter subsequence ending in a(14) with a unique ordinal transform exists in the sequence thus far. For example, a(15) cannot be 5 because the length-5 subsequence a(10..14) = 3,2,2,2,3 has the same multiset as that of the subsequence a(9..13) = 3,3,2,2,2. %Y A378876 Cf. A376937, A375207, A377079. %K A378876 nonn %O A378876 1,3 %A A378876 _Neal Gersh Tolunsky_, Jan 17 2025