21147

Appears in sequences

• Bell or exponential numbers: number of ways to partition a set of n labeled elements.at n=9A000110
• Triangle a(n,k) of number of M-sequences read by antidiagonals.at n=74A007723
• a(n) is the concatenation of n and 7n.at n=20A009441
• M-sequences m_0,...,m_7 with m_1 < n.at n=3A011823
• Aitken's array: triangle of numbers {a(n,k), n >= 0, 0 <= k <= n} read by rows, defined by a(0,0)=1, a(n,0) = a(n-1,n-1), a(n,k) = a(n,k-1) + a(n-1,k-1).at n=44A011971
• Aitken's array: triangle of numbers {a(n,k), n >= 0, 0 <= k <= n} read by rows, defined by a(0,0)=1, a(n,0) = a(n-1,n-1), a(n,k) = a(n,k-1) + a(n-1,k-1).at n=45A011971
• Sequence formed by reading rows of triangle defined in A011971.at n=36A011972
• Triangle of coefficients of ordered cycle-index polynomials: T(n,k) = binomial(n,k)*Bell(k)*Bell(n-k).at n=45A033306
• Triangle of coefficients of ordered cycle-index polynomials: T(n,k) = binomial(n,k)*Bell(k)*Bell(n-k).at n=54A033306
• Triangle of a(n,k) = number of minimal covers of an n-set that cover k points of that set uniquely (n >= 1, k >= 1).at n=44A035347
• Triangle of coefficients arising in calculation of A002872 and A002874 (sorting numbers).at n=36A036073
• Matrix square of Stirling2 triangle A008277: 2-levels set partitions of [n] into k first-level subsets.at n=36A039810
• Triangle of generalized Stirling numbers of 2nd kind.at n=44A046817
• Triangle of numbers a(n,k), 0 <= k <= n: number of set partitions of {1,2,...,n} in which exactly k of the blocks have been distinguished.at n=45A049020
• Number of trees with n nodes and 4 leaves.at n=42A055291
• Exponential transform of Pascal's triangle A007318.at n=45A055883
• Exponential transform of Stirling2 triangle A008277.at n=44A055896
• Exponential transform of Stirling1 triangle A008275.at n=44A055924
• Triangle read by rows: T(n,c) = number of successive equalities in set partitions of n.at n=45A056857
• Triangle T(n,k) = number of element-subset partitions of {1..n} with n-k+1 equalities (n >= 1, 1 <= k <= n).at n=54A056860