56320

Appears in sequences

• a(n) = binomial(n,2) * 2^(n-1).at n=11A001815
• Generalized tangent numbers.at n=3A002303
• Triangle of coefficients in expansion of D^n (tan x) in powers of tan x.at n=25A008293
• a(n) = (2*n - 9)*n^2.at n=32A015243
• Triangle read by rows: T(n,k) = number of paths of n upsteps U and n downsteps D that contain k UUDs.at n=37A051288
• Fourth unsigned column of Lanczos triangle A053125 (decreasing powers).at n=4A054322
• 12-almost primes (generalization of semiprimes).at n=30A069273
• Numbers k such that core(k) = b(k,1)*b(k,0) where b(k,1) is the number of 1's in binary representation of k, b(k,0) the number of 0's and core(k) the squarefree part of k.at n=4A071639
• A transform of C(n,3).at n=9A082138
• Triangle read by rows: nonzero coefficients of the polynomials F_n(x) which express derivatives of tan(z) in terms of powers of tan(z).at n=27A101343
• a(n) = 2^n * Fibonacci(n).at n=10A103435
• Triangle T(n,k), 0 <= k <= n, read by rows, defined by T(0,0) = 1; T(0,k) = 0 if k < 0 or if k > 0; T(n,k) = k*T(n-1,k-1) + (k+2)*T(n-1,k+1).at n=38A107729
• Even refactorable numbers n such that the number r of odd divisors and the number s of even divisors are both even divisors of n and n is the first number for which the triple (r,s,t) occurs, where t is the number of divisors of n.at n=32A120356
• A triangular sequence of four back recursive polynomial that are Hermite H(x,n) like and alternating orthogonal on domain {-Infinity,Infinity} and weight function Exp[ -x^2/2]: P(x, n) = 2*x*P(x, n - 1) - n*P(x, n - 2) + 4*x^3*P(x, n - 3)-n^2*P(x, n - 4).at n=59A138092
• Triangle read by rows: coefficients in polynomials P_n(u) arising from the expansion of D^(n-1) (tan x) in increasing powers of tan x for n>=1 and 1 for n=0.at n=48A155100
• a(1) = 1, a(n) = 2*a(n-1) if n is even; a(n) = a(n-1)*Fibonacci((n+1)/2)/Fibonacci((n-1)/2) if n is odd.at n=19A171648
• Numbers with 44 divisors.at n=7A175751
• Number of 3-step king's tours on an n X n board summed over all starting positions.at n=32A186862
• The arithmetic mean of the prime factors (with multiplicity) of n is 3.at n=41A200612
• Let f_k(n) be the result of applying phi (the Euler totient function A000010) k times to n; a(n) = n*Product_{k=1..oo} f_k(n).at n=43A291782