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 A045982 #17 Feb 16 2025 08:32:38 %S A045982 1,11,31,311311,31131113211321,3113111321132113211331131221131211, %T A045982 31131113211321132113311312211312111321133113122113122113122123211311222113111221 %N A045982 Describe all the previous terms!. %C A045982 Previous terms are concatenated into one large integer. %C A045982 Next terms are 184, 420, 958 and 2194 digits long. %H A045982 Reinhard Zumkeller, <a href="/A045982/b045982.txt">Table of n, a(n) for n = 1..10</a> %H A045982 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LookandSaySequence.html">Look and Say Sequence</a>. %H A045982 Wikipedia, <a href="http://en.wikipedia.org/wiki/Look-and-say_sequence">Look-and-say sequence</a>. %o A045982 (Haskell) %o A045982 a045982 n = a045982_list !! (n-1) %o A045982 a045982_list = 1 : f [1] where %o A045982 f xs = y : f (xs ++ [y]) where %o A045982 y = a045918 $ read (concatMap show xs) %o A045982 -- _Reinhard Zumkeller_, Feb 28 2014 %Y A045982 Cf. A005150, A045981. %Y A045982 Cf. A045918. %K A045982 nonn,easy,base,nice %O A045982 1,2 %A A045982 _N. J. A. Sloane_ %E A045982 More terms from _Patrick De Geest_, Jun 15 1999