A086879 Number of symmetric singular n X n matrices over GF(2).

1, 4, 36, 576, 18880, 1208320, 155553792, 39821770752, 20417644331008, 20907667794952192, 42834024773286100992, 175448165471379869663232, 1437398154830976169705209856, 23550331368750713564450158280704

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Formula

a(n) = 2^(n*(n+1)/2) - A086812(n).

Crossrefs

Cf. A086812.

Sequence in context: A306736 A307845 A346292 * A372241 A363010 A263445

Adjacent sequences: A086876 A086877 A086878 * A086880 A086881 A086882

Keyword

nonn

Author

Yuval Dekel (dekelyuval(AT)hotmail.com), Sep 16 2003

Extensions

More terms from Ray Chandler, Sep 19 2003

Status

approved