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 A284432 #8 Feb 06 2025 21:33:24 %S A284432 1,1,2,2,4,4,4,48,48,144,144,144,2160,8496,21312,110592,203904,407808, %T A284432 815616,1631232,15667200,31334400,445114368,890228736,7291772928, %U A284432 14583545856,36458864640,72917729280,145835458560,1694545920000,16054441574400,101226251059200,421941436416000,2144473989120000,13603849760931840 %N A284432 The number of positive integer sequences of length n with no duplicate substrings (forward or backward) of length greater than 1 and a minimal sum (= A282168(n)). %e A284432 For n = 7 the a(7) = 4 solutions are: %e A284432 [1,3,3,2,2,1,1], %e A284432 [1,2,2,3,3,1,1], %e A284432 [1,1,3,3,2,2,1], and %e A284432 [1,1,2,2,3,3,1]. %Y A284432 Cf. A282168, A283558, A284431, A284433, A284435. %K A284432 nonn %O A284432 1,3 %A A284432 _Peter Kagey_, Mar 27 2017 %E A284432 Terms a(11) onward from _Max Alekseyev_, Feb 06 2025