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 A292946 #8 Sep 30 2017 16:07:43 %S A292946 0,0,0,0,0,0,0,1,0,0,0,0,0,0,2,2,0,0,0,1,0,0,0,0,0,0,0,1,4,4,4,5,0,0, %T A292946 0,0,0,0,2,2,0,0,0,1,0,0,0,0,0,0,0,0,0,0,2,3,8,8,8,8,8,8,10,10,0,0,0, %U A292946 1,0,0,0,0,0,0,0,1,4,4,4,5,0,0,0,0,0,0,2,2,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,1,0,0 %N A292946 a(n) = A292945(A163511(n)). %C A292946 Because A292945(n) = a(A243071(n)), the sequence works as a "masking function" where the 1-bits in a(n) (always a subset of the 1-bits in binary expansion of n) indicate which numbers are of the form 6k+5 in binary tree A163511 (or its mirror image tree A005940) on that trajectory which leads from the root of the tree to the node containing A163511(n). %C A292946 The AND - XOR formulas just restate the fact that J(-3|n) = J(-1|n)*J(3|n), as the Jacobi-symbol is multiplicative (also) with respect to its upper argument. %H A292946 Antti Karttunen, <a href="/A292946/b292946.txt">Table of n, a(n) for n = 0..8191</a> %H A292946 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %H A292946 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %F A292946 a(n) = A292945(A163511(n)). %F A292946 a(n) = A292264(n) AND (A292256(n) XOR A292274(n)), where AND is bitwise-and (A004198) and XOR is bitwise-XOR (A003987). %F A292946 a(n) = A292264(n) AND (A292254(n) XOR A292271(n)). [See comments.] %F A292946 For all n >= 0, A292942(n) + A292944(n) + a(n) = n. %o A292946 (Scheme) (define (A292946 n) (A292945 (A163511 n))) %Y A292946 Cf. A005940, A163511, A292945. %Y A292946 Cf. also A292247, A292248, A292254, A292256, A292264, A292271, A292274, A292592, A292593, A292942, A292944 (for similarly constructed sequences). %K A292946 nonn %O A292946 0,15 %A A292946 _Antti Karttunen_, Sep 28 2017