%I #8 Jun 16 2018 18:30:51
%S 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,
%T 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,
%U 0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1
%N a(n) = 1 if n is composite and the n-th Stern polynomial B(n,x) is irreducible, 0 otherwise.
%C Characteristic function for A186892, apart from its initial term.
%C See also A186891 about related Ulas & Ulas conjecture.
%H Antti Karttunen, <a href="/A305892/b305892.txt">Table of n, a(n) for n = 1..65537</a>
%H <a href="/index/Ch#char_fns">Index entries for characteristic functions</a>
%F a(n) = (1-A010051(n))*A283991(n).
%o (PARI)
%o ps(n)=if(n<2, n, if(n%2, ps(n\2)+ps(n\2+1), 'x*ps(n\2)));
%o A305892(n) = (!isprime(n) && polisirreducible(ps(n))); \\ _Antti Karttunen_, Jun 16 2018, after _Charles R Greathouse IV_'s Apr 07 2015 code for A186892.
%Y Cf. A010051, A186891, A186892, A283991, A284011.
%Y Differs from A305821 for the first time at n=65, where a(65) = 1, while A305821(65) = 0.
%K nonn
%O 1
%A _Antti Karttunen_, Jun 16 2018
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