699136

Appears in sequences

• Number of subsets of {1,2,3,...,n} that sum to 0 mod 3.at n=21A068010
• Number of closed walks of length 2n at any of the nodes of degree 1 on the graph of the (7,4) Hamming code.at n=8A103334
• Two-colorings of triangular arrays under rotational symmetries.at n=6A241806
• Array read by antidiagonals: T(n,k) is the number of nonisomorphic k-tuples of involutions on a (2n)-set that pairwise commute.at n=58A362903
• Table read by downward antidiagonals: T(n,k) is the number of tilings of the n X k cylinder by two distinct tiles.at n=38A368264