187425

Appears in sequences

• a(n) = T(n,n+2), T given by A027052.at n=18A027053
• E.g.f. x*(c(x/2)-1)/(1-2*x), where c(x) = g.f. for Catalan numbers A000108.at n=6A035101
• The convolution matrix of the double factorial of odd numbers (A001147).at n=22A035342
• Triangle T(n, k, q) = t(n,q)/(t(k,q)*t(n-k,q)), where t(n, k) = Product_{j=1..n} q-Pochhammer(j, k+1, k+1)/(1-(k+1))^j and t(n, 0) = n!, with q = 3, read by rows.at n=12A156952
• Expansion of 1/(1 - 10*x + 9*x^2)^(3/2).at n=5A331516
• Sum of the positive differences of the cubed parts in each partition of n into two parts.at n=30A335639
• 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=22A336599
• Number of regular polygons that can be drawn with vertices on a centered hexagonal grid with side length n.at n=17A339483
• Smallest number having exactly n divisors of the form 8*k + 1.at n=17A343104
• Positions of records in A188169.at n=11A343134
• Odd nonsquares k for which A161942(k) >= k, where A161942 is the odd part of sigma.at n=5A348743
• Terms of A363691 with a record number of divisors.at n=14A363693
• Odd nondeficient numbers of the form p^(1+4k) * r^2, where p is prime of the form 1+4m, r > 1, and gcd(p,r) = 1.at n=5A386427
• a(n) = Sum_{k=0..n} 4^k * binomial(n,k) * binomial(n+3,k).at n=5A388206