A283979 a(n) = (n XOR A264977(n))/4, where XOR is bitwise-xor (A003987).

0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 2, 3, 0, 3, 0, 0, 0, 7, 6, 5, 4, 4, 6, 7, 0, 5, 6, 5, 0, 7, 0, 0, 0, 15, 14, 9, 12, 10, 10, 9, 8, 10, 8, 8, 12, 10, 14, 15, 0, 9, 10, 15, 12, 14, 10, 9, 0, 9, 14, 9, 0, 15, 0, 0, 0, 31, 30, 17, 28, 22, 18, 21, 24, 20, 20, 18, 20, 16, 18, 17, 16, 22, 20, 22, 16, 21, 16, 16, 24, 16, 20, 18, 28, 22, 30, 31, 0, 17, 18, 27, 20, 28, 30

Offset: 0

Author

Antti Karttunen, Mar 25 2017

Keywords

• nonn
• base
• look

Links

• Antti Karttunen, Table of n, a(n) for n = 0..8191
• Index entries for sequences related to binary expansion of n

Crossrefs

Cf. A003987, A264977, A265397, A284013.

Programs

Mathematica

A264977[n_]:= If[n<2, n, If[EvenQ[n], 2 A264977[n/2], BitXor[A264977[(n - 1)/2], A264977[(n + 1)/2]]]]; Table[BitXor[n, A264977[n]]/4, {n, 0, 100}] (* Indranil Ghosh, Mar 28 2017 *)

PARI

a(n) = if(n<2, n, if(n%2, bitxor(a((n - 1)/2), a((n + 1)/2)), 2*a(n/2)));
for(n=0, 150, print1(bitxor(n, a(n))/4,", ")) \\ Indranil Ghosh, Mar 28 2017

Scheme

(define (A283979 n) (/ (A003987bi n (A264977 n)) 4)) ;; Where A003987bi implements bitwise-xor (A003987).

Formula

a(n) = (n XOR A264977(n))/4, where XOR is bitwise-xor (A003987).