360783593

Appears in sequences

• Number of 2-factors in P_8 X P_n.at n=7A145417
• Number of ways to cover the 2n X 2n grid graph by vertex disjoint cycles.at n=3A222202
• Write n=3i+j, 0<=j<3; a(n) = number of ways to cover the r X s grid graph by vertex disjoint cycles, where (r,s) = (2i+2, 2i+2) (if j=0), (2i+2, 2i+3) (if j=1) or (2i+3, 2i+4) (if j=2).at n=9A222204