A357811 Number of n-step closed paths on the Cairo pentagonal lattice graph starting from a degree-3 node.

1, 0, 3, 0, 17, 6, 115, 100, 867, 1236, 7117, 13770, 62545, 146866, 579387, 1537920, 5581725, 16002810, 55329435, 166465820, 559913787, 1736268432, 5752600961, 18182999274, 59777071435, 191287075320

Offset: 0

Author

Dave R.M. Langers, Oct 13 2022

Keywords

• nonn
• easy
• walk

Examples

			For n=2, the a(2) = 3 solutions visit one of the three vertices adjacent to the initial vertex, and then return.
For n=5, the a(5) = 6 solutions consist of counterclockwise or clockwise traversals of the circumference of any of the three pentagons that surround the initial vertex.
		

Links

• Wikipedia, Cairo pentagonal tiling

Crossrefs

The accompanying sequences for the number of paths that return to a degree-4 node is A357810.

Similar sequences for square, hexagonal, and honeycomb lattices are A002894, A002898 and A002893.