This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A091245 #8 Sep 02 2015 10:52:02 %S A091245 0,0,0,0,1,2,3,3,4,5,6,6,7,7,8,9,10,11,12,12,13,14,15,16,17,17,18,19, %T A091245 20,21,22,22,23,24,25,26,27,27,28,29,30,30,31,32,33,34,35,35,36,37,38, %U A091245 39,40,41,42,42,43,44,45,45,46,46,47,48,49,50,51,51,52,53,54,55,56,56 %N A091245 Number of reducible GF(2)[X]-polynomials in range [0,n]. %C A091245 Analogous to A065855. %H A091245 A. Karttunen, <a href="/A091247/a091247.scm.txt">Scheme-program for computing this sequence.</a> %H A091245 <a href="/index/Ge#GF2X">Index entries for sequences operating on GF(2)[X]-polynomials</a> %e A091245 In range [0,8] there are the following four reducible polynomials: 4,5,6,8 thus a(8) = 4. %o A091245 (PARI) first(n)=my(s); concat([0,0], vector(n-1,k, s += !polisirreducible(Pol(binary(k+1))*Mod(1,2)))) \\ _Charles R Greathouse IV_, Sep 02 2015 %Y A091245 Partial sums of A091247. Cf. A091242. %K A091245 nonn %O A091245 0,6 %A A091245 _Antti Karttunen_, Jan 03 2004