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 A264972 #17 Jun 02 2025 12:15:36 %S A264972 262,670,1450,1690,2158,4246,19522,18410,34678,36926,118882,146998, %T A264972 290566,377966,240038,381466,407054,178898,147146,149714,159458, %U A264972 149378,129242,117958,157822,350014,489878,180770,155930,395686,510386,292426,514294,503114,264490,435670,482882,311674,452774,353570,323374,369638,321926,293726 %N A264972 Trajectory of 262 under repeated application of the permutation A264965: a(0) = 262; for n >= 1, a(n) = A264965(a(n-1)). %C A264972 The trajectory is probably infinite, not periodic. %H A264972 Antti Karttunen, <a href="/A264972/b264972.txt">Table of n, a(n) for n = 0..1000</a> %F A264972 a(0) = 262; for n >= 1, a(n) = A264965(a(n-1)). %e A264972 a(0) = 262 by definition. Its binary representation is A007088(262) = 100000110. When we reverse the significant prefix (i.e., leave the trailing zeros where they are), we get 386 (A007088(386) = 110000010). 386's ternary representation is A007089(386) = 112022. Reversing the significant prefix (now the whole expansion because no trailing zeros present), we get 220211 (= A007089(670)), thus a(1) = 670. %o A264972 (Scheme, with memoizing macro definec) %o A264972 (definec (A264972 n) (if (zero? n) 262 (A264965 (A264972 (- n 1))))) %Y A264972 Cf. A007088, A007089, A264965, A264969, A264973. %K A264972 nonn,look,base %O A264972 0,1 %A A264972 _Antti Karttunen_, Dec 06 2015