This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A357811 #11 Nov 27 2022 11:32:27 %S A357811 1,0,3,0,17,6,115,100,867,1236,7117,13770,62545,146866,579387,1537920, %T A357811 5581725,16002810,55329435,166465820,559913787,1736268432,5752600961, %U A357811 18182999274,59777071435,191287075320 %N A357811 Number of n-step closed paths on the Cairo pentagonal lattice graph starting from a degree-3 node. %H A357811 Wikipedia, <a href="https://en.wikipedia.org/wiki/Cairo_pentagonal_tiling">Cairo pentagonal tiling</a> %e A357811 For n=2, the a(2) = 3 solutions visit one of the three vertices adjacent to the initial vertex, and then return. %e A357811 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. %Y A357811 The accompanying sequences for the number of paths that return to a degree-4 node is A357810. %Y A357811 Similar sequences for square, hexagonal, and honeycomb lattices are A002894, A002898 and A002893. %K A357811 nonn,easy,walk %O A357811 0,3 %A A357811 _Dave R.M. Langers_, Oct 13 2022