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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
OFFSET
0,9
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. A118666 (positions of zeros).
Sequence in context: A019787 A093202 A019765 * A059965 A124930 A195202
KEYWORD
nonn,base,look
AUTHOR
Antti Karttunen, Jan 09 2017
STATUS
approved