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 A284433 #10 Feb 06 2025 21:33:33 %S A284433 1,2,6,2,18,12,24,24,1320,240,528,720,5664,105888,16992,150048,244800, %T A284433 4266432,4375296,39598848,50637312,123310080,202549248,15925690368, %U A284433 3765657600,23454351360,101739110400,437749678080,1572538613760,11891771080704,7862693068800,185042766200832 %N A284433 The number of positive integer sequences of length n with no duplicate substrings (forward or backward) of length greater than 1, every number different from its neighbors, and a minimal sum (= A282167(n)). %e A284433 For n = 4 the a(4) = 2 solutions are [1,3,2,1] and [1,2,3,1]. %Y A284433 Cf. A282167, A283558, A284431, A284432, A284436. %K A284433 nonn %O A284433 1,2 %A A284433 _Peter Kagey_, Mar 27 2017 %E A284433 Terms a(10) onward from _Max Alekseyev_, Feb 06 2025