A379118 - OEIS

%I #8 Dec 17 2024 19:52:05

%S 0,0,0,0,0,1,0,0,0,1,0,1,0,1,1,0,0,0,0,1,1,1,0,1,0,1,0,1,0,1,0,0,1,0,

%T 1,0,0,0,1,1,0,1,0,1,0,1,0,1,0,1,1,1,0,0,1,1,1,1,0,1,0,1,1,0,1,1,0,0,

%U 1,1,0,1,0,0,1,1,1,1,0,1,0,0,0,1,0,1,1,1,0,0,1,1,1,1,0,1,0,0,0,1,0,1,0,1,1,0,0,1,0,0,1,1,0,1,1,1,0,1,1,1

%N Characteristic function of A379114, numbers k that have a proper unitary divisor d > 1 such that A048720(A065621(sigma(d)),sigma(k/d)) is equal to sigma(k).

%H Antti Karttunen, <a href="/A379118/b379118.txt">Table of n, a(n) for n = 1..100000</a>

%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>

%H <a href="/index/Con#CongruCrossDomain">Index entries for sequences defined by congruent products between domains N and GF(2)[X]</a>.

%H <a href="/index/Ge#GF2X">Index entries for sequences related to polynomials in ring GF(2)[X]</a>.

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

%F a(n) = [A379113(n) > 1], where [ ] is the Iverson bracket.

%o (PARI) A379118(n) = (A379113(n)>1);

%Y Cf. A000203, A048720, A065621, A379113, A379114.

%K nonn,new

%O 1

%A _Antti Karttunen_, Dec 17 2024