cp's OEIS Frontend

A341273 If A261283(n) = 0, then a(n) = n, otherwise a(n) is obtained by flipping the A261283(n)-th rightmost bit in the binary expansion of n.

%I A341273 #13 Feb 09 2021 11:54:42
%S A341273 0,0,0,7,0,7,7,7,0,25,42,75,76,45,30,7,0,25,82,51,52,85,30,7,25,25,30,
%T A341273 25,30,25,30,30,0,97,42,51,52,45,102,7,42,45,42,42,45,45,42,45,52,51,
%U A341273 51,51,52,52,52,51,120,25,42,51,52,45,30,127,0,97,82,75
%N A341273 If A261283(n) = 0, then a(n) = n, otherwise a(n) is obtained by flipping the A261283(n)-th rightmost bit in the binary expansion of n.
%C A341273 All terms belong to A075926.
%H A341273 Rémy Sigrist, <a href="/A341273/b341273.txt">Table of n, a(n) for n = 0..32768</a>
%F A341273 A261283(a(n)) = 0.
%F A341273 a(a(n)) = a(n).
%F A341273 a(n) = n iff n belongs to A075926.
%F A341273 a(2^k) = 0 for any k >= 0.
%e A341273 For n = 7:
%e A341273 - A261283(7) = 0,
%e A341273 - so a(7) = 7.
%e A341273 For n = 43:
%e A341273 - A261283(43) = 1,
%e A341273 - so a(43) is obtained by flipping the rightmost binary digit in 43,
%e A341273 - a(43) = 42.
%o A341273 (PARI) a(n) = { my (m=n, x=0); while (m, my (v=valuation(m, 2)); x=bitxor(x, v+1); m-=2^v); if (x, bitxor(n, 2^(x-1)), n) }
%Y A341273 Cf. A075926, A261283.
%K A341273 nonn,look,base
%O A341273 0,4
%A A341273 _Rémy Sigrist_, Feb 08 2021