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 A292373 #12 Jun 30 2022 12:51:47 %S A292373 0,0,0,1,0,0,0,1,0,0,0,1,2,2,2,3,0,0,0,1,0,0,0,1,0,0,0,1,2,2,2,3,0,0, %T A292373 0,1,0,0,0,1,0,0,0,1,2,2,2,3,4,4,4,5,4,4,4,5,4,4,4,5,6,6,6,7,0,0,0,1, %U A292373 0,0,0,1,0,0,0,1,2,2,2,3,0,0,0,1,0,0,0,1,0,0,0,1,2,2,2,3,0,0,0,1,0,0,0,1,0,0,0,1,2,2,2,3,4,4,4,5,4,4,4,5,4 %N A292373 A binary encoding of 3-digits in base-4 representation of n. %H A292373 Antti Karttunen, <a href="/A292373/b292373.txt">Table of n, a(n) for n = 0..65536</a> %H A292373 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %F A292373 a(n) = A059905(A048735(n)) = A059906(A213370(n)). %F A292373 For all n >= 0, A000120(a(n)) = A160383(n). %e A292373 n a(n) base-4(n) binary(a(n)) %e A292373 A007090(n) A007088(a(n)) %e A292373 -- ---- ---------- ------------ %e A292373 1 0 1 0 %e A292373 2 0 2 0 %e A292373 3 1 3 1 %e A292373 4 0 10 0 %e A292373 5 0 11 0 %e A292373 6 0 12 0 %e A292373 7 1 13 1 %e A292373 8 0 20 0 %e A292373 9 0 21 0 %e A292373 10 0 22 0 %e A292373 11 1 23 1 %e A292373 12 2 30 10 %e A292373 13 2 31 10 %e A292373 14 2 32 10 %e A292373 15 3 33 11 %e A292373 16 0 100 0 %e A292373 17 0 101 0 %e A292373 18 0 102 0 %e A292373 19 1 103 1 %o A292373 (Scheme, with memoization-macro definec) %o A292373 (definec (A292373 n) (if (zero? n) n (let ((d (modulo n 4))) (+ (if (= 3 d) 1 0) (* 2 (A292373 (/ (- n d) 4))))))) %o A292373 (Python) %o A292373 def A292373(n): return int(bin(n&n>>1)[:1:-2][::-1],2) # _Chai Wah Wu_, Jun 30 2022 %Y A292373 Cf. A007088, A007090, A048735, A059905, A059906, A160383, A213370, A292370, A292371, A292372. %K A292373 nonn,base %O A292373 0,13 %A A292373 _Antti Karttunen_, Sep 15 2017