151335135

Appears in sequences

• a(n) = (n-1)!! - (n-2)!!.at n=16A007911
• a(n) = (2*n+2)!! - (2*n+1)!!.at n=8A129890
• Triangle read by rows: T(n,k) (1 <= k <= n-1, n >= 2) = d(2*(n-k)-1)*(d(2*n-2)/d(2*(n-k)-2) - d(2*n-3)/d(2*(n-k)-3)), where d = A006882 is the double factorial function.at n=44A202212
• Triangle of coefficients T(n,k) of polynomials p(n,x) = Sum_{k=0..n} T(n,k)*x^k where T(0,0) = 1, and T(n,k) = 0 for k < 0 or k > n, and T(n,k) = T(n-1,k-1) + (2*n-1+k)*T(n-1,k) for n > 0 and 0 <= k <= n.at n=46A265649
• Triangle read by rows: T(n,k) is the number of linear chord diagrams on 2n vertices with one marked chord such that exactly k of the remaining n-1 chords are contained within the marked chord.at n=36A336599