%I A128902
%S A128902 0,0,0,1,2,7,14,34,72,157,326,689,1418,2935,6010,12304,25058,51004,
%T A128902 103478,209767,424430,858019,1732430,3495434,7046432,14196421,
%U A128902 28583424,57522469,115704938,232645189,467597246,939526144
%N A128902 Number of degree n polynomials over GF(2) (with non-zero constant term) 
               at Hamming distance 2 from some irreducible polynomial.
%H A128902 G. Lee, F. Ruskey and A. Williams, <a href="http://www.cs.uvic.ca/~ruskey/
               Publications/DistGF2/DistGF2.html">Hamming distance from irreducible 
               polynomials over GF(2)</a>
%e A128902 The coefficient vectors of the three degree 4 irreducible polynomials 
               are 10011, 11111 and 11001. There is only one polynomial whose Hamming 
               distance is two (or more) from all of them, namely 10101. Thus a(4) 
               = |{10101}| = 1.
%Y A128902 Sequence in context: A140253 A018453 A000147 this_sequence A060552 A167762 
               A018497
%Y A128902 Adjacent sequences: A128899 A128900 A128901 this_sequence A128903 A128904 
               A128905
%K A128902 nonn
%O A128902 1,5
%A A128902 Frank Ruskey (ruskey(AT)cs.uvic.ca), Apr 22 2007