A257000 - OEIS

%I #14 Dec 20 2021 08:11:48

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

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

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

%N Characteristic function for A206074.

%H Antti Karttunen, <a href="/A257000/b257000.txt">Table of n, a(n) for n = 0..65537</a>

%t binPol[n_, x_] := With[{bb = IntegerDigits[n, 2]}, bb.x^Range[Length[bb]-1, 0, -1]];

%t a[n_] := If[IrreduciblePolynomialQ[binPol[n, x]], 1, 0];

%t a /@ Range[0, 128] (* _Jean-François Alcover_, Dec 20 2021 *)

%o (PARI)

%o A257000(n) = polisirreducible(Pol(binary(n)));

%o for(n=0, 8191, write("b257000.txt", n, " ", A257000(n)));

%Y Partial sums: A255574.

%Y Cf. A010051, A091225, A206074, A304751.

%K nonn

%O 0

%A _Antti Karttunen_, May 14 2015