191268

Appears in sequences

• a(n) = binomial(2*n, n) mod ((n+1)*(n+2)*(n+3)*(n+4)).at n=19A065346
• a(n) = (1)*(2 + 3 + 4 + ... + n) + (1 + 2)*(3 + 4 + 5 + ... + n) + (1 + 2 + 3)*(4 + 5 + 6 + ... + n) + ... + (1 + 2 + 3 + ... + n-1)*n.at n=21A067056
• Number of noncrossing connected graphs on n nodes having exactly two interior faces.at n=5A089433
• Triangle read by rows: T(n,k) (n >= 2, k >= 0) is the number of non-crossing connected graphs on n nodes on a circle, having k interior faces. Rows are indexed 2,3,4,...; columns are indexed 0,1,2,....at n=30A089434
• Denominators of e.g.f.: tan(arccosh(x)) = cot(arcsinh(x)).at n=21A102062
• Denominators of e.g.f. cosec(arctanh(x)).at n=21A102077
• Triangle read by rows: T(n,k) (n >= 2, 1 <= k <= 2n-3) is the number of non-crossing connected graphs on n nodes on a circle, having k edges. Rows are indexed 2,3,4,...; columns are indexed 0,1,2,....at n=58A127537