A280507 - OEIS

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A280507

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

3

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

(list; graph; refs; listen; history; text; internal format)

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