A194779 Number of lower triangles of a (2n-1)X(2n-1) 0..n array with new values introduced in row major order 0..n and no element unequal to more than one horizontal or vertical neighbor

1, 7, 43, 268, 1740, 11862, 85013, 639760, 5045610, 41615165, 358185399, 3210667490, 29914284833, 289187621900, 2895861006415

Offset

1,2

Comments

Row 1 of A194778

Links

Table of n, a(n) for n=1..15.

Example

All solutions for n=2 containing a 2
..0
..1.1
..1.1.2

Crossrefs

Sequence in context: A022036 A277670 A015451 * A126502 A378565 A286911

Adjacent sequences: A194776 A194777 A194778 * A194780 A194781 A194782

Keyword

nonn

Author

R. H. Hardin Sep 02 2011

Status

approved