Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A132452
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A132452 First primitive GF(2)[X] polynomials of degree n with exactly 5 terms, X^n suppressed. +0
5
0, 0, 0, 0, 15, 27, 15, 29, 27, 27, 23, 83, 27, 43, 23, 45, 15, 39, 39, 83, 39, 57, 43, 27, 15, 71, 39, 83, 23, 83, 15, 197, 83, 281, 387, 387 (list; graph; listen)
OFFSET

1,5

COMMENT

More precisely: minimum value for X=2 of GF(2)[X] polynomials P[X] of degree less than n and exactly 4 terms such that X^n+P[X] is primitive, or 0 if no such polynomial exists. Applications include maxmimum-length linear feedback shift registers with efficient implementation in both hardware and software. Proof is needed that there exists a primitive GF(2)[X] polynomial P[X] of degree n and exactly 5 terms for all n>4.

LINKS

Index entries for sequences operating on GF(2)[X]-polynomials

EXAMPLE

a(11)=23, or 10111 in binary, representing the GF(2)[X] polynomial X^4+X^2+X^1+1, because X^11+X^4+X^2+X^1+1 has exactly 5 terms and it is primitive, contrary to X^11+X^3+X^2+X^1+1.

CROSSREFS

For n>4, 2^n+a(n) belongs to A091250. A132451(n) = a(n)+2^n and gives the corresponding primitive polynomial. Cf. A132448, similar with no restriction on number of terms. Cf. A132450, similar with restriction to at most 5 terms. Cf. A132454, similar with restriction to minimal number of terms.

Sequence in context: A139566 A097963 A063936 this_sequence A063552 A131541 A080945

Adjacent sequences: A132449 A132450 A132451 this_sequence A132453 A132454 A132455

KEYWORD

more,nonn

AUTHOR

Francois R. Grieu (f(AT)grieu.com), Aug 22 2007

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 8 08:31 EST 2009. Contains 170430 sequences.


AT&T Labs Research