A187463 Number of 3X3 0..n arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.

26, 1236, 13726, 84048, 325932, 1118854, 2843394, 6976192, 14900828, 30426976, 54176690, 102373984, 165774050, 274508960, 439528372, 685793860, 988022550, 1499573556, 2077344368, 3019161806, 4198346324, 5736736398, 7500683014

Offset

1,1

Comments

Row 2 of A187462

Links

R. H. Hardin, Table of n, a(n) for n = 1..40

Crossrefs

Sequence in context: A037138 A091429 A200721 * A160311 A220955 A106710

Adjacent sequences: A187460 A187461 A187462 * A187464 A187465 A187466

Keyword

nonn

Author

R. H. Hardin, Mar 10 2011

Status

approved