67584

Appears in sequences

• a(n) = n*(n+1)*2^(n-2).at n=11A001788
• Triangle whose (i,j)-th entry is binomial(i,j)*4^(i-j)*11^j.at n=22A038241
• Triangle whose (i,j)-th entry is binomial(i,j)*11^(i-j)*4^j.at n=26A038318
• 13-almost primes (generalization of semiprimes).at n=15A069274
• Let P(n,X) = Product_{i=1..2n+1} (X - 1/cos(Pi*k/(2n+1))); then P(n,X) is a polynomial with integer coefficients. Sequences gives maximum values of absolute values of coefficients of P(n,X).at n=7A075581
• E.g.f.: log((1+x) / (1-x)) / (2*(1-x)).at n=8A081358
• Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n, having k ddu's [here u = (1,1) and d = (1,-1)].at n=44A091894
• Expansion of e.g.f. sin(x)^2 * sinh(x)^2.at n=2A107391
• a(n) = Sum_{r < n, gcd(r,n)=1} n!/r.at n=7A110376
• 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=37A120356
• Triangular vector sequence as weighted conversion between A137286 and A049310.at n=48A136664
• Second differences of even superperfect numbers A061652, divided by 2.at n=4A139237
• Second differences of Mersenne numbers A001348, divided by 4.at n=5A139243
• Triangle read by rows: T(n,k) = number of AVL trees of height n with k (leaf-) nodes, n>=0, fibonacci(n+2)<=k<=2^n.at n=39A143897
• E.g.f.: Sum_{n>=0} tan(2^n*x)^n/n!.at n=4A168404
• Molecular topological indices of the complete graph K_n.at n=32A181617
• Integer coefficient array for polynomials related to the minimal polynomials of cos(2Pi/n). Rising powers of x.at n=160A181877
• a(n) = (n/4)*2^(n/2)*((1+sqrt(2))^2 + (-1)^n*(1-sqrt(2))^2).at n=22A187272
• Numbers k such that (number of prime factors of k counted with multiplicity) less (number of distinct prime factors of k) = 10.at n=23A195069
• Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of f(i,j) = gcd(i+1, j+1) (A204030).at n=44A204111