1931540

Appears in sequences

• a(n) = 3*(2*n)!/((n+2)!*(n-1)!).at n=13A000245
• Number of n-bead bracelets (turnover necklaces) of two colors with 10 red beads and n-10 black beads.at n=24A005515
• a(n) = T(n, floor(n/2)), where T = Catalan triangle (A008315).at n=25A026008
• Number of nonnegative integer 4 X 4 matrices with sum of elements equal to n, up to rotational symmetry.at n=11A054773
• a(n) = 3*binomial(2n, n-1)/(n+2), n > 0, with a(0)=1.at n=13A071724
• Largest gcd of two distinct numbers on row n of Pascal's triangle.at n=24A092394
• Isomers of polyenes attached to benzene (see Cyvin et al. for precise definition).at n=25A121094
• Row sums of the inverse of number triangle A(n,k) = 1/C(n) if k <= n <= 2k, 0 otherwise, where C(n) = A000108(n).at n=14A127768
• a(n) = 3*C(4*n-2,2*n)/(2*n+1) - 2*0^n.at n=7A127769
• Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n having k LD's (n>=0; 0<=k<=floor((n-1)/2)).at n=42A128733
• Triangle read by rows: T(n,k) = (4k+3)/(n+2k+2)*binomial(2n,n+2k+1).at n=43A158483
• Lexicographically earliest sequence of distinct positive integers with no finite subset summing to a Catalan number (A000108).at n=35A353983
• Arises from enumeration of a certain class of partial zig-zag knight's paths on the square grid.at n=25A368379