A091257 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),...

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

Offset: 1

Author

Antti Karttunen, Jan 03 2004

Keywords

• nonn
• look
• tabl

Comments

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

Links

• Alois P. Heinz, Antidiagonals n = 1..200, flattened
• A. Karttunen, Scheme-program for computing this sequence.
• Index entries for sequences operating on GF(2)[X]-polynomials

Crossrefs

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].