61921

Appears in sequences

• Let S(x,y) = number of lattice paths from (0,0) to (x,y) that use the step set { (0,1), (1,0), (2,0), (3,0), ...} and never pass below y = x. Sequence gives S(n-1,n) = number of 'Schröder' trees with n+1 leaves and root of degree 2.at n=8A010683
• Triangle of numbers S(x,y) = number of lattice paths from (0,0) to (x,y) that use step set { (0,1), (1,0), (2,0), (3,0), ....} and never pass below y = x.at n=53A011117
• Gaps of 10 in sequence A038593 (lower terms).at n=26A038659
• Triangle read by rows: T(n,k) is the number of dissections of a convex n-gon by nonintersecting diagonals, having a k-gon over a fixed edge (base).at n=36A091370
• a(n) = n*(n^3-n^2+n+1)/2.at n=19A100855
• Triangle read by rows: T(n,k) is number of Schroeder paths of length 2n and having k peaks at height 1, for 0 <= k <= n.at n=46A104219
• The sum of the next n terms of A114103.at n=18A114105
• Numbers with sum of digits = 19, divisible by 19 and containing the string "19".at n=10A121669
• Schroeder triangle sums: a(2*n-1) = A010683(2*n-2) and a(2*n) = A010683(2*n-1) - A001003(2*n-1).at n=8A227506
• Numbers n such that (n^n-2)/(n-2) is an integer.at n=43A242787
• Main diagonal of Unlucky array: a(n) = A255543(n,n).at n=40A255549
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 846", based on the 5-celled von Neumann neighborhood.at n=8A273688
• a(n) = n^4 * Sum_{p|n, p prime} 1/p^4.at n=29A351244
• Least k such that the k-th maximal run of nonsquarefree numbers has length n. Position of first appearance of n in A053797.at n=6A373199