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 A264969 #7 Dec 06 2015 21:07:25 %S A264969 1,1,1,1,1,2,1,2,1,1,1,5,1,5,3,2,1,5,1,5,1,2,3,5,1,5,3,1,1,5,1,22,2,3, %T A264969 9,7,1,22,9,3,1,22,2,7,4,2,9,1,1,7,9,4,4,7,1,5,1,3,9,5,1,1,3,2,2,5,2, %U A264969 22,1,2,9,18,1,7,3,4,4,18,4,7,1,2,3,18,1,3,10,3,10,18,1,3,8,6,3,22,2,22,9,4,4,18,3,17,10,4,10,6,1,3,3,6,1,18,4,17,8,3,3,10,1,7 %N A264969 Cycle length of n under bijection A264965 / A264966. %C A264969 By convention: a(n) = 0 if the cycle where n resides can be proven to be infinite. a(n) = -1 is the placeholder value if the cycle where n resides is only suspected to be infinite. %C A264969 Is n=262 the first representative of runaway cycle? See A264972 and A264973. %H A264969 Antti Karttunen, <a href="/A264969/b264969.txt">Table of n, a(n) for n = 0..261</a> %e A264969 A264965(5) = 7 and A264965(7) = 5, thus a(5) = a(7) = 2. %o A264969 (Scheme) %o A264969 ;; Very naive program which succumbs to the first infinite cycle: %o A264969 (define (A264969 n) (let loop ((s 1) (next (A264965 n))) (if (equal? next n) s (loop (+ 1 s) (A264965 next))))) %Y A264969 Cf. A264965, A264966, A264972, A264973. %K A264969 nonn %O A264969 0,6 %A A264969 _Antti Karttunen_, Dec 06 2015