20643840

Appears in sequences

• Number of similarity classes of descendants created by bisection refinement from an initial n-simplex.at n=6A019999
• a(n) = 2^n*(n-1)! for n > 1, a(1) = 1.at n=8A032184
• a(n) is the n-th quartic factorial number divided by 4.at n=6A034177
• Triangle of coefficients of certain exponential convolution polynomials.at n=21A048786
• E.g.f.: x/(1-4*x).at n=7A052570
• Least number whose number of divisors is n-th term from A014613 (numbers of form p*q*r*s, products of exactly 4 primes, counted with multiplicity).at n=25A061218
• Denominators in the series for Bessel function J7(x).at n=1A061406
• Number of necklaces with n labeled beads of 2 colors.at n=8A066318
• 4th-order non-linear ("factorial") recursion: a(0)=a(1)=a(2)=a(3)=1, a(n) = (n+1)*a(n-4).at n=27A081407
• a(n) = n!*n^3.at n=8A091363
• Duplicate of A032184.at n=7A130683
• A triangular sequence from coefficients of an expansion of the Poisson's kernel: p(t,r)=(1-r^2)/(1-2*r*Cos(t)+r^2): r->t;Cos(t)->x.at n=42A137511
• A triangular sequence of coefficients based on an expansion of a Skew Catenoid of Matthius Weber like Sheffer expansion function: g(t) = x*(3 + t^2)/(t^2 - 1); f(t) = (3 + t^2)/(t^2 - 1); p(x,t) = Exp[x*(t)]*(1 - f(t)2).at n=21A137528
• A triangular sequence of coefficients based on an expansion of a Skew Catenoid of Matthius Weber like Sheffer expansion function: g(t) = x*(3 + t^2)/(t^2 - 1); f(t) = (3 + t^2)/(t^2 - 1); p(x,t) = Exp[x*(t)]*(1 - f(t)2).at n=25A137528
• Number of directed Hamiltonian paths in the 2n-crossed prism graph.at n=12A137885
• Triangle read by rows: T(n,m)=floor[(m/n)*row(n)].at n=47A152969
• The decomposition of a certain labeled universe (A052584), triangle read by rows.at n=44A159749
• Number of permutations of 1..n with i-10<=p(i)<=i+7.at n=10A179367
• Number of ways to choose a factorization of each integer from 2 to n into factors > 1.at n=26A321514
• Denominators arising in the expansion of Sum_{k>=1} (1/(4k^2-1)^n) in even powers of Pi.at n=7A382783