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 A080303 #10 Jan 11 2024 10:24:43
%S A080303 4,1,12,3,100,25,28,7,804,201,204,51,228,57,60,15,6436,1609,1612,403,
%T A080303 1636,409,412,103,1828,457,460,115,484,121,124,31,51492,12873,12876,
%U A080303 3219,12900,3225,3228,807,13092,3273,3276,819,3300,825,828,207,14628
%N A080303 Rewrite 0->100 in the binary expansion of n.
%H A080303 Harvey P. Dale, <a href="/A080303/b080303.txt">Table of n, a(n) for n = 0..1000</a>
%e A080303 2 = 10 in binary, is rewritten as 1100 so a(2)=12.
%e A080303 4 = 100 in binary, is rewritten as 1100100 which is 100 as decimal number, thus a(4)=100.
%e A080303 5 = 101 in binary, is rewritten as 11001, 25 in binary, thus a(5)=25.
%t A080303 Table[FromDigits[Flatten[IntegerDigits[n,2]/.(0->{1,0,0})],2],{n,0,80}] (* _Harvey P. Dale_, Aug 19 2021 *)
%o A080303 (Scheme) (define (A080303 n) (cond ((zero? n) 4) ((= n 1) n) ((odd? n) (+ 1 (* 2 (A080303 (/ (- n 1) 2))))) (else (+ 4 (* 8 (A080303 (/ n 2)))))))
%Y A080303 Cf. A080310.
%K A080303 nonn,base
%O A080303 0,1
%A A080303 _Antti Karttunen_, Mar 02 2003