51640

Appears in sequences

• Numbers having four 7's in base 9.at n=25A043484
• Triangle T(n,k) (n >= 2, k = 3..n+floor(n/2)) giving number of bicoverings of an n-set with k blocks.at n=24A059443
• Number of 8-block bicoverings of an n-set.at n=6A059949
• Triangle read by rows: T(n,k) gives the number of set partitions of {1,...,n} with maximum block length k.at n=47A080510
• Number of n X 2 0..2 arrays with row sums equal and column sums unequal to adjacent columns.at n=9A203485
• Numbers m such that m, m' and m'' are in arithmetic progression, where m' and m'' are the first and second arithmetic derivatives of m.at n=24A212409
• Number of set partitions of {1,...,n} with largest set of size 3.at n=7A229245