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A296203 Xor-Moebius transform of A000203, the sum of divisors. 4

%I #15 Dec 26 2017 18:03:21

%S 1,2,5,4,7,10,9,8,9,22,13,20,15,18,27,16,19,34,21,60,45,42,25,40,25,

%T 38,37,36,31,78,33,32,57,38,63,108,39,42,51,120,43,90,45,116,95,82,49,

%U 80,49,86,95,76,55,122,67,72,65,70,61,204,63,66,65,64,93,130,69,76,125,166,73,184,75,86,125,180,101,190,81,240,81

%N Xor-Moebius transform of A000203, the sum of divisors.

%C 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.

%H Antti Karttunen, <a href="/A296203/b296203.txt">Table of n, a(n) for n = 1..16384</a>

%H Rémy Sigrist, <a href="/A295901/a295901_1.png">Scatterplot of the first 2^16 terms</a>

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

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

%K nonn

%O 1,2

%A _Antti Karttunen_, Dec 25 2017, from _Rémy Sigrist_'s "gallery of scatter plots" in A295901.

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Last modified April 24 03:08 EDT 2024. Contains 371918 sequences. (Running on oeis4.)