A280507 a(n) = n XOR A193231(n).

0, 0, 1, 1, 1, 1, 0, 0, 7, 7, 6, 6, 6, 6, 7, 7, 1, 1, 0, 0, 0, 0, 1, 1, 6, 6, 7, 7, 7, 7, 6, 6, 19, 19, 18, 18, 18, 18, 19, 19, 20, 20, 21, 21, 21, 21, 20, 20, 18, 18, 19, 19, 19, 19, 18, 18, 21, 21, 20, 20, 20, 20, 21, 21, 21, 21, 20, 20, 20, 20, 21, 21, 18, 18, 19, 19, 19, 19, 18, 18, 20, 20, 21, 21, 21, 21, 20, 20, 19, 19, 18, 18, 18, 18, 19, 19, 6, 6

Offset

0,9

Links

Antti Karttunen, Table of n, a(n) for n = 0..16383

Index entries for sequences related to binary expansion of n

Index entries for sequences operating on polynomials in ring GF(2)[X]

Formula

a(n) = A003987(n,A193231(n)) = n XOR A193231(n).

Other identities. For all n >= 0:

a(A193231(n)) = a(n).

Prog

(PARI)
A193231(n) = { my(x='x); subst(lift(Mod(1, 2)*subst(Pol(binary(n), x), x, 1+x)), x, 2) }; \\ From A193231
A280507(n) = bitxor(n, A193231(n)); \\ Antti Karttunen, Feb 15 2021
(Scheme) (define (A280507 n) (A003987bi n (A193231 n))) ;; Where A003987bi implements A003987 (bitwise-XOR).

Crossrefs

Cf. A003987, A193231, A280501, A280502, A280508.

Cf. A118666 (positions of zeros).

Sequence in context: A019787 A093202 A019765 * A059965 A124930 A195202

Adjacent sequences: A280504 A280505 A280506 * A280508 A280509 A280510

Keyword

nonn,base,look

Author

Antti Karttunen, Jan 09 2017

Status

approved