A378230 - OEIS

%I #7 Nov 26 2024 15:21:52

%S 6,14,28,42,50,62,72,114,124,150,186,248,254,376,402,412,426,434,474,

%T 496,498,508,762,784,786,796,868,938,978,994,1002,1016,1302,1528,1568,

%U 1578,1626,1778,1834,1852,1888,1948,1988,2032,3056,3064,3094,3282,3350,3556,3568,3644,3682,3794,3858,3868,3882,3954,4064

%N Positions of 0's in A378226, where A278226 is XOR-Moebius transform of A318457, and A318457(n) = n XOR (sigma(n)-n).

%H Antti Karttunen, <a href="/A378230/b378230.txt">Table of n, a(n) for n = 1..9001</a>

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>

%H <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>

%o (PARI)

%o A318457(n) = bitxor(n,sigma(n)-n);

%o A378226(n) = { my(v=0); fordiv(n, d, if(issquarefree(n/d), v=bitxor(v, A318457(d)))); (v); }

%o isA378230(n) = (0==A378226(n));

%Y Positions of 0's in A378226.

%Y Cf. A001065, A318457.

%Y Subsequences: A000396 (at least the even terms).

%K nonn

%O 1,1

%A _Antti Karttunen_, Nov 26 2024