524880

Appears in sequences

• Triple factorial numbers a(n) = n!!!, defined by a(n) = n*a(n-3), a(0) = a(1) = 1, a(2) = 2. Sometimes written n!3.at n=18A007661
• Triple factorial numbers: (3n)!!! = 3^n*n!.at n=6A032031
• Dirichlet convolution of b_n = 2^(n-1) with phi(n).at n=19A034738
• Triangle read by rows: a(n, m) = S1(n, m)*3^(n-m), where S1 are the signed Stirling numbers of first kind A008275 (n >= 1, 1 <= m <= n).at n=21A051141
• Jordan function J_4(n).at n=26A059377
• a(n)=-1/b(2n) where 1/(e^y-e^(y/3))= sum(i=-1,inf,b(i)*y^i).at n=3A068181
• a(n) = (n^3 + n^2)*9^n.at n=3A129009
• Table T(n,k) = n!*k^n, read by upwards antidiagonals.at n=48A131182
• a(n) = n^6 - n^4.at n=9A136038
• Triple factorial array, read by antidiagonals, where row n+1 is generated from row n by first removing terms in row n at positions {[m*(m+5)/6], m >= 0} and then taking partial sums, starting with all 1's in row 0.at n=38A136212
• Triple factorials n!!!: a(n) = n*a(n-3).at n=18A161474
• a(n) = Product_{k in M_n} k, M_n = {k | 1 <= k <= 3n and k mod 3 = n mod 3}.at n=6A190903
• Monotonic ordering of nonnegative differences 3^i-9^j, for 40>=i>=0, j>=0.at n=38A192157
• Monotonic ordering of nonnegative differences 9^i-3^j, for 40>= i>=0, j>=0.at n=34A192158
• Number of spanning trees in the n-Sierpinski gasket graph.at n=2A193256
• Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of (3i-2 if i=j and = 0 otherwise), as in A204160.at n=27A204161
• Triangle read by rows, k!*S_3(n, k) where S_m(n, k) are the Stirling-Frobenius subset numbers of order m; n >= 0, k >= 0.at n=27A225472
• a(n) = 5*n^4.at n=18A269792
• Triangle read by rows: T(n, k) = S2[3,1](n, k)*k! with the Sheffer triangle S2[3,1] = (exp(x), exp(3*x) -1) given in A282629.at n=27A284861
• Triangle read by rows, generalized Eulerian polynomials evaluated at x = 1.at n=24A337997