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 A305420 #8 Jun 08 2018 13:52:33 %S A305420 2,3,7,7,7,7,11,11,11,11,13,13,19,19,19,19,19,19,25,25,25,25,25,25,31, %T A305420 31,31,31,31,31,37,37,37,37,37,37,41,41,41,41,47,47,47,47,47,47,55,55, %U A305420 55,55,55,55,55,55,59,59,59,59,61,61,67,67,67,67,67,67,73,73,73,73,73,73,87,87,87,87,87,87,87,87,87,87,87,87,87,87,91 %N A305420 Smallest k > n whose binary expansion encodes an irreducible (0,1)-polynomial over GF(2)[X]. %C A305420 a(n) is the smallest term of A014580 greater than n. %H A305420 Antti Karttunen, <a href="/A305420/b305420.txt">Table of n, a(n) for n = 1..21845</a> %H A305420 <a href="/index/Ge#GF2X">Index entries for sequences related to polynomials in ring GF(2)[X]</a> %F A305420 For n >= 1, a(n) = A091228(1+n). %o A305420 (PARI) %o A305420 A091225(n) = polisirreducible(Pol(binary(n))*Mod(1, 2)); %o A305420 A305420(n) = { my(k=1+n); while(!A091225(k),k++); (k); }; %Y A305420 Cf. A014580, A091225, A091228, A305419, A305421. %Y A305420 Cf. also A151800, A305430. %K A305420 nonn %O A305420 1,1 %A A305420 _Antti Karttunen_, Jun 07 2018