This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
Table[DigitCount[2 n - DigitCount[2 n, 2, 1], 2, 1], {n, 0, 120}] (* Michael De Vlieger, Mar 18 2017 *)
b(n) = if(n<1, 0, b(n\2) + n%2); for(n=0, 150, print1(b(2*n - b(2*n)), ", ")) \\ Indranil Ghosh, Mar 21 2017
def A(n): return bin(2*n - bin(2*n)[2:].count("1"))[2:].count("1")
print([A(n) for n in range(151)]) # Indranil Ghosh, Mar 21 2017
(define (A280700 n) (A000120 (A005187 n)))
Table[BitXor[n, 2 # - DigitCount[2 #, 2, 1] &@ Floor[n/2]], {n, 0, 106}] (* Michael De Vlieger, Mar 20 2017 *)
b(n) = if(n<1, 0, b(n\2) + n%2); A(n) = 2*n - b(2*n); for(n=0, 110, print1(bitxor(n, A(floor(n/2))),", ")) \\ Indranil Ghosh, Mar 25 2017
def A(n): return 2*n - bin(2*n)[2:].count("1")
print([n^A(n//2) for n in range(111)]) # Indranil Ghosh, Mar 25 2017
(define (A283997 n) (A003987bi n (A005187 (floor->exact (/ n 2))))) ;; Where A003987bi implements bitwise-XOR (A003987).
Function[t, BitXor @@ # & /@ Transpose@ {Rest@ t, Most@ t}]@ Complement[Range@ Last@ #, #] &@ Table[IntegerExponent[(2 n)!, 2], {n, 0, 112}] (* Michael De Vlieger, Mar 15 2017, after Jean-François Alcover at A055938 *)
(define (A279353 n) (A003987bi (A055938 (+ 1 n)) (A055938 n))) ;; Here A003987bi implements a bitwise-XOR (A003987).