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 A380001 #9 Jan 11 2025 04:01:28
%S A380001 0,1,13,109,877,7021,56173,449389,3595117,28760941,230087533,
%T A380001 1840700269,14725602157,117804817261,942438538093,7539508304749,
%U A380001 60316066437997,482528531503981,3860228252031853,30881826016254829,247054608130038637,1976436865040309101,15811494920322472813
%N A380001 Fixed points of A378299.
%H A380001 Paolo Xausa, <a href="/A380001/b380001.txt">Table of n, a(n) for n = 0..1000</a>
%H A380001 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (9,-8).
%F A380001 a(0) = 0; a(n) = 8*a(n-1) + 5, for n >= 1.
%e A380001 For n >= 1, the binary representation of a(n) is 1 followed by (101 repeated n-1 times).
%e A380001 E.g., a(5) = 7021 = (1 101 101 101 101)_2.
%t A380001 Join[{0}, NestList[8*# + 5 &, 1, 25]]
%Y A380001 Cf. A378299.
%K A380001 nonn,base,easy
%O A380001 0,3
%A A380001 _Paolo Xausa_, Jan 10 2025