2257920

Appears in sequences

• a(n) = Sum_{k=1..n-1} k^2*sigma(k)*sigma(n-k).at n=27A000477
• a(n) = n! * binomial(n,3).at n=5A001805
• a(n) = n! * binomial(n,5).at n=3A001807
• Exponential generating function = (1+2*x)/(1-2*x)^3.at n=6A014479
• Permanent of the n X n (0,1)-matrices with ij-th entry equal to zero iff (i=1,j=1),(i=1,j=n),(i=n,j=1) and (i=n,j=n).at n=7A098916
• Product ceiling(n/1)*ceiling(n/2)*ceiling(n/3)*...*ceiling(n/n) (the 'ceiling factorial').at n=14A131385
• Triangle of f-vectors of the simplicial complexes dual to the permutohedra of type B_n.at n=34A145901
• Irregular triangle T(n,k) = A096162(n,k) * A036040(n,k) * A048996(n,k) * A098546(n,k) * A178886(n,k), read by rows, 1 <= k <= A000041(n).at n=47A179236
• Triangle T(n, k) read by rows, T(n, k) = n!*binomial(n, k).at n=39A196347
• Triangle T(n, k) read by rows, T(n, k) = n!*binomial(n, k).at n=41A196347
• Triangle read by rows, k!*2^k*s_2(n, k) where s_m(n, k) are the Stirling-Frobenius cycle numbers of order m; n >= 0, k >= 0.at n=34A225474
• Triangular array read by rows: T(n,k) is the number of f:{1,2,...,n}->{1,2,...,n} with exactly 2k elements that have a preimage of even (possibly zero) cardinality; n>=0, 0<=k<=floor(n/2).at n=21A225942
• Triangle read by rows. A generalization of unsigned Lah numbers, called L[2,1].at n=29A286724
• Interpolating the factorial and the powers of 2. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=38A331333
• Expansion of e.g.f. x^3/(1-x-x^2-x^3)^2.at n=8A365330
• Triangle read by rows: n-th row polynomial equals the numerator of the rational function (-1)^n*f(x) * (d/dx)^n (1/f(x)), where f(x) = sqrt(x + x^2).at n=34A368235