264539520

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=24A007661
• Triple factorial numbers: (3n)!!! = 3^n*n!.at n=8A032031
• 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=36A051141
• Expansion of e.g.f. x^3/(1-3*x).at n=9A052678
• a(n)=-1/b(2n) where 1/(e^y-e^(y/3))= sum(i=-1,inf,b(i)*y^i).at n=4A068181
• a(n) = n!*n^3.at n=9A091363
• Triple factorials n!!!: a(n) = n*a(n-3).at n=24A161474
• 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=44A284861