Two virtually identical responses regarding Lisa Langsetmo's sequence...DMD _______________________________________________________ Date: Sat, 5 Feb 2000 13:48:14 +0000 From: John Hunton Subject: Re: a sequence The On-Line Encyclopedia of Integer Sequences, http://www.research.att.com/~njas/sequences/index.html reckons Sequence: 1,2,2,8,8,48,16,96,128 Name: Minimal number of cosets in an orthogonal sublattice of A_n (minimal number of paths in any trellis diagram). References A.H. Banihashemi, ``Decoding complexity and trellis structure of lattices," Ph.D. dissertation, E&CE Dept., Univ. of Waterloo, Waterloo, Ont., Canada, 1997. A.H. Banihashemi and I.F. Blake, ``On the trellis complexity of root lattices and their duals," submitted to IEEE Trans. Inform. Theory, Apr. 1997. A.H. Banihashemi and I.F. Blake, ``Minimal trellis diagrams of lattices, Proc. IEEE International Symp. on Inform. Theory, Ulm, Germany, p. 434. Keywords: nonn Offset: 1 Author(s): Amir H. Banihashemi (ahashemi@shannon.uwaterloo.ca) John Hunton. _______________________________________________ Date: Sat, 05 Feb 2000 09:30:49 -0500 From: "Jay A. Wood" Subject: Your sequence Lisa, Neil Sloane at AT&T Shannon Labs has an on-line encyclopedia of integer sequences: http://www.research.att.com/~njas/sequences/index.html I ran 1, 2, 2, 8, 8, 48, 16, 96, 128, and received the following reply: ID Number: A016119 Sequence: 1,2,2,8,8,48,16,96,128 Name: Minimal number of cosets in an orthogonal sublattice of A_n (minimal number of paths in any trellis diagram). References A.H. Banihashemi, ``Decoding complexity and trellis structure of lattices," Ph.D. dissertation, E&CE Dept., Univ. of Waterloo, Waterloo, Ont., Canada, 1997. A.H. Banihashemi and I.F. Blake, ``On the trellis complexity of root lattices and their duals," submitted to IEEE Trans. Inform. Theory, Apr. 1997. A.H. Banihashemi and I.F. Blake, ``Minimal trellis diagrams of lattices, Proc. IEEE International Symp. on Inform. Theory, Ulm, Germany, p. 434. Keywords: nonn Offset: 1 Author(s): Amir H. Banihashemi (ahashemi@shannon.uwaterloo.ca) Jay Wood -- % Jay A. Wood % 219-247-1954 (home); 219-631-6498 (work: Notre Dame, Spr 2000) % mailto:wood@calumet.purdue.edu % http://www.calumet.purdue.edu/public/math/wood/