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 A307095 #17 Jun 05 2019 11:49:09 %S A307095 1,1,2,4,2,4,3,3,2,4,6,5,7,2,4,3,5,7,9,11,13,3,2,4,6,8,10,12,14,16,18, %T A307095 20,22,6,3,2,4,6,5,7,2,4,3,3,2,4,6,8,10,12,6,5,7,2,4,3,5,7,9,11,13,3, %U A307095 2,4,6,5,7,2,4,3,5,7,6,3,2,4,6,8,10,12,2,4 %N A307095 Let K_n = prefix of length n of Kolakoski sequence A000002; a(n) is the length of the longest palindromic suffix of K_n. %H A307095 Rémy Sigrist, <a href="/A307095/b307095.txt">Table of n, a(n) for n = 1..10000</a> %H A307095 Rémy Sigrist, <a href="/A307095/a307095.gp.txt">PARI program for A307095</a> %F A307095 a(n+1) <= a(n) + 2. %e A307095 The first terms, alongside K_n with longest palindromic suffix in parentheses, are: %e A307095 n a(n) K_n %e A307095 -- ---- ------------------ %e A307095 1 1 (1) %e A307095 2 1 1(2) %e A307095 3 2 1(22) %e A307095 4 4 (1221) %e A307095 5 2 122(11) %e A307095 6 4 12(2112) %e A307095 7 3 1221(121) %e A307095 8 3 12211(212) %e A307095 9 2 1221121(22) %e A307095 10 4 122112(1221) %e A307095 11 6 12211(212212) %e A307095 12 5 1221121(22122) %e A307095 13 7 122112(1221221) %e A307095 14 2 122112122122(11) %e A307095 15 4 12211212212(2112) %e A307095 16 3 1221121221221(121) %o A307095 (PARI) See Links section. %Y A307095 See A220080 for a similar sequence. %Y A307095 Cf. A000002. %K A307095 nonn %O A307095 1,3 %A A307095 _Rémy Sigrist_, Jun 04 2019