A162128 Number of n X n symmetric 0..3 arrays with rows, considered as 4-ary numbers, in strictly increasing order

4, 30, 720, 53505, 12680820, 9936894780, 26516959720695, 246350237314954005, 8100725881546916639370, 954991817788505196528852930, 407790975833063512191532123109595

Offset

1,1

Links

R. H. Hardin, Table of n, a(n) for n=1..13

Crossrefs

Sequence in context: A163885 A120338 A064050 * A337969 A234566 A365366

Adjacent sequences: A162125 A162126 A162127 * A162129 A162130 A162131

Keyword

nonn

Author

R. H. Hardin Jun 25 2009

Status

approved