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 A255420 #24 May 13 2019 15:56:11 %S A255420 1,2,3,5,11,37,181,1361,13927,183871,3005533,59045717 %N A255420 Ludic recurrence: Iterates of f(n) = A003309(n+1) starting from n=1. %H A255420 Donovan Johnson, <a href="/A255420/a255420.txt">Ludic numbers computed up to A003309(1236290) = 23000711</a> %F A255420 a(0) = 1; for n >= 1: a(n) = A003309(1+a(n-1)). %F A255420 Other identities. For all n >= 0: %F A255420 a(n) = A237126(A000225(n+1)). %F A255420 a(n) = A255421(A007097(n)). %o A255420 (Scheme, with memoization-macro definec) %o A255420 (definec (A255420 n) (if (zero? n) 1 (A003309 (+ 1 (A255420 (- n 1)))))) %o A255420 (Haskell) %o A255420 a255420 n = a255420_list !! n %o A255420 a255420_list = iterate (a003309 . (+ 1)) 1 %o A255420 -- _Reinhard Zumkeller_, Feb 25 2015 %Y A255420 Cf. A000225, A003309, A007097, A237126, A255421. %K A255420 nonn,more %O A255420 0,2 %A A255420 _Antti Karttunen_, Feb 23 2015