A057411 Number of staircase polygons of perimeter 2n with 2 (staircase polygon) holes on square lattice (not allowing rotations).

2, 54, 737, 7330, 60362, 438284, 2908069, 18032906, 106088843, 598428100, 3261717223, 17278076588, 89351738840, 452686823796, 2253216812878, 11043624323310, 53399946187312, 255135202590382, 1206067676613670

Offset

12,1

Links

I. Jensen, Table of n, a(n) for n = 12..75 (from link below)

I. Jensen, More terms

Crossrefs

Sequence in context: A200195 A202739 A055024 * A157058 A305693 A357421

Adjacent sequences: A057408 A057409 A057410 * A057412 A057413 A057414

Keyword

nonn

Author

N. J. A. Sloane, Aug 30 2000

Status

approved