251328

Appears in sequences

• a(n) = floor(n*(n-1)*(n-2)*(n-3)/5).at n=35A011915
• Number of permutations of length n which avoid the patterns 2341, 4123, 4132.at n=11A116780
• Number of subsets of {1,...,n} containing {a,a+4} for some a.at n=18A209408
• Number of (w,x,y,z) with all terms in {1,...,n} and w>=2x and y<=3z.at n=33A212521
• 4-level binary fanout graph coloring a rectangular array: number of n X 1 0..14 arrays where 0..14 label nodes of a graph with edges 0,1 1,3 3,5 3,6 1,4 4,7 4,8 0,2 2,9 9,11 9,12 2,10 10,13 10,14 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.at n=12A223442
• a(n) is the number of ways to make a Secret Santa assignment among n couples such that no one gets their partner's name and if A gets B's name, B does not get A's name.at n=4A367537