A077556 Meandric numbers for an undirected line crossing two perpendicular roads at n points, beginning in the (-,-) quadrant, crossing x axis first and ending in any quadrant.

0, 1, 2, 5, 12, 31, 81, 239

Offset: 0

Author

N. J. A. Sloane and Jon Wild, Aug 25 2003

Keywords

• nonn
• more

Crossrefs

Similar to A077551 but line is undirected.