33360

Appears in sequences

• Coefficient of q^3 in nu(n), where nu(0)=1, nu(1)=b and, for n>=2, nu(n)=b*nu(n-1)+lambda*(1+q+q^2+...+q^(n-2))*nu(n-2) with (b,lambda)=(1,1).at n=16A074083
• Triangle read by rows: T(n,k) is the number of noncrossing trees with n edges in which the leftmost leaf is at level k.at n=51A101409
• Number of ways of arranging 2n tokens in a row, with 2 copies of each token from 1 through n, such that between every pair of tokens labeled i (i=1..n) there is exactly one taken labeled (i+1 mod n).at n=5A117515
• Expansion of g.f.: 1/((1 - x^2 - x^3 - x^4 - x^5 - x^6 - x^7)*(1 + x + x^2 + x^3 + x^4 + x^5 - x^7)).at n=27A147605
• Number of permutations of floor(i*7/5), i=0..n-1, with all sums of 5 adjacent terms unique.at n=7A152360
• a(n) = Sum_{k=0..n} binomial(n, k - 1)*(1 - k)^(k - 1)*(n - k)*(n - k + 1)^(n - k).at n=6A368981