1,2

Unique sequence satisfying SumXOR_{d divides n} a(d) = sigma(n) for all n > 0, where SumXOR is the analog of summation under the binary XOR operation. See A295901 for a list of some of the properties of Xor-Moebius transform.

Antti Karttunen, Table of n, a(n) for n = 1..16384

Rémy Sigrist, Scatterplot of the first 2^16 terms

(PARI) A296203(n) = { my(v=0); fordiv(n, d, if(issquarefree(n/d), v=bitxor(v, sigma(d)))); (v); } \\ after code in A295901.

Cf. A000203, A169813, A256739, A295901, A296208.

Sequence in context: A153990 A154811 A309513 * A036237 A015948 A119733

Adjacent sequences: A296200 A296201 A296202 * A296204 A296205 A296206

nonn

Antti Karttunen, Dec 25 2017, from Rémy Sigrist's "gallery of scatter plots" in A295901.

approved