21380

Appears in sequences

• Number of (n+1)X3 0..2 arrays with the permanents of all 2X2 subblocks equal and nonzero.at n=4A204834
• Number of (n+1)X6 0..2 arrays with the permanents of all 2X2 subblocks equal and nonzero.at n=1A204837
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the permanents of all 2X2 subblocks equal and nonzero.at n=16A204840
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the permanents of all 2X2 subblocks equal and nonzero.at n=19A204840
• Number of ways to reciprocally link elements of an nX4 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without consecutive collinear links.at n=4A220677
• Number of ways to reciprocally link elements of an nX5 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without consecutive collinear links.at n=3A220678
• T(n,k)=Number of ways to reciprocally link elements of an nXk array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without consecutive collinear links.at n=31A220681
• T(n,k)=Number of ways to reciprocally link elements of an nXk array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without consecutive collinear links.at n=32A220681
• E.g.f. A(x) satisfies: A(x)^2 = -x*log(1-A(x)) where A(x) = Sum_{n>=1} a(n)*x^n/n!^2.at n=4A226057
• Number of permutations of [n] avoiding {4213, 1432, 1324}.at n=10A294767
• Array read by antidiagonals: A(n,k) is the number of sets of nonempty subsets of a k-element set where each element appears in at most n subsets.at n=50A330964
• A331757(n)/2.at n=18A331758
• Minimal number of moves for the cyclic variant of Hanoi's tower for 4 pegs and n disks, with the final peg one step away.at n=15A338024
• Array read by antidiagonals: T(n,k) is the number of homeomorphically irreducible leaf colored trees with n leaves of k colors.at n=73A339779
• Number of homeomorphically irreducible leaf colored trees with n leaves of 4 colors.at n=7A339784