A091257 - OEIS

%I #18 Oct 26 2022 15:46:43

%S 1,2,2,3,4,3,4,6,6,4,5,8,5,8,5,6,10,12,12,10,6,7,12,15,16,15,12,7,8,

%T 14,10,20,20,10,14,8,9,16,9,24,17,24,9,16,9,10,18,24,28,30,30,28,24,

%U 18,10,11,20,27,32,27,20,27,32,27,20,11,12,22,30,36,40,18,18,40,36,30,22,12

%N Multiplication table A x B computed for polynomials over GF(2), where (A,B) runs as (1,1),(1,2),(2,1),(1,3),(2,2),(3,1),...

%C Essentially same as A048720 but computed starting from offset one instead of zero. Analogous to A003991. Each n occurs A091220(n) times.

%H Alois P. Heinz, <a href="/A091257/b091257.txt">Antidiagonals n = 1..200, flattened</a>

%H A. Karttunen, <a href="/A091247/a091247.scm.txt">Scheme-program for computing this sequence.</a>

%H <a href="/index/Ge#GF2X">Index entries for sequences operating on GF(2)[X]-polynomials</a>

%Y a(n) = A048720bi(A091255(n), A091256(n)) because the identity A x B = gcd(A, B) x lcm(A, B) holds also in the polynomial ring GF(2)[X].

%K nonn,look,tabl

%O 1,2

%A _Antti Karttunen_, Jan 03 2004