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a(n) = Number of terms larger than one in range 0 .. n of A205783.
7

%I #9 May 14 2015 15:57:36

%S 0,0,0,0,1,1,2,2,3,4,5,5,6,6,7,8,9,9,10,10,11,12,13,13,14,14,15,16,17,

%T 17,18,18,19,20,21,22,23,23,24,25,26,26,27,27,28,29,30,30,31,32,33,34,

%U 35,35,36,36,37,38,39,39,40,40,41,42,43,44,45,45,46,46,47,47,48,48,49,50,51,51,52,52,53,53

%N a(n) = Number of terms larger than one in range 0 .. n of A205783.

%H Antti Karttunen, <a href="/A255572/b255572.txt">Table of n, a(n) for n = 0..8192</a>

%F Other identities and observations. For all n >= 1:

%F a(n) = A255573(n) - 1.

%F a(n) <= A065855(n).

%F a(n) <= A091245(n).

%o (PARI)

%o A255572_write_bfile(up_to_n) = { my(n,a_n=0); for(n=0, up_to_n, if(((n > 1) && !polisirreducible(Pol(binary(n)))),a_n++); write("b255572.txt", n, " ", a_n)); };

%o A255572_write_bfile(8192);

%Y Essentially one less than A255573 (after the initial zero).

%Y Cf. A065855, A091245, A205783, A255574.

%K nonn

%O 0,7

%A _Antti Karttunen_, May 14 2015