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 A305892 a(n) = 1 if n is composite and the n-th Stern polynomial B(n,x) is irreducible, 0 otherwise. 2
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 OFFSET 1 COMMENTS Characteristic function for A186892, apart from its initial term. See also A186891 about related Ulas & Ulas conjecture. LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 FORMULA a(n) = (1-A010051(n))*A283991(n). PROG (PARI) ps(n)=if(n<2, n, if(n%2, ps(n\2)+ps(n\2+1), 'x*ps(n\2))); A305892(n) = (!isprime(n) && polisirreducible(ps(n))); \\ Antti Karttunen, Jun 16 2018, after Charles R Greathouse IV's Apr 07 2015 code for A186892. CROSSREFS Cf. A010051, A186891, A186892, A283991, A284011. Differs from A305821 for the first time at n=65, where a(65) = 1, while A305821(65) = 0. Sequence in context: A011739 A023975 A305821 * A324870 A011738 A011737 Adjacent sequences:  A305889 A305890 A305891 * A305893 A305894 A305895 KEYWORD nonn AUTHOR Antti Karttunen, Jun 16 2018 STATUS approved

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Last modified October 19 11:09 EDT 2019. Contains 328216 sequences. (Running on oeis4.)