%I #10 May 11 2019 18:32:50

%S 69,77,81,121,169,205,209,261,265,275,289,295,305,321,323,327,329,339,

%T 377,405,407,437,453,473,475,481,493,517,533,551,553,555,559,565,575,

%U 581,583,595,625,649,667,671,699,703,707,737,747,749,755,763,767,779,785,805,815,833,835,849,851,855,861,869,871,885,893,905,923,925

%N Numbers n such that for any divisor d of n and some k, A048720(d,k) = n only for trivial cases d=1 and d=n, despite that n is neither prime nor in A014580.

%H Antti Karttunen, <a href="/A325386/b325386.txt">Table of n, a(n) for n = 1..20000</a>

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

%o (PARI)

%o A325560(n) = { my(p = Pol(binary(n))*Mod(1, 2)); sumdiv(n,d,my(q = Pol(binary(d))*Mod(1, 2)); !(p%q)); };

%o isA325386(n) = (!isprime(n) && !polisirreducible(Pol(binary(n))*Mod(1,2)) && (2 == A325560(n)));

%Y Terms of A325559 not in A257688.

%Y Subsequence of A005408 (odd numbers).

%Y Cf. A014580, A325560.

%Y Differs from A260428 for the first time at n=32, where a(32) = 555, a value missing from A260428.

%K nonn

%O 1,1

%A _Antti Karttunen_, May 11 2019