18976

Appears in sequences

• a(n) = (n+1)*(5*n^2+4*n+1).at n=15A027849
• a(n) = 8*a(n-1) -15*a(n-2), a(0)=1, a(1)=16.at n=5A081194
• G.f. A(x) satisfies x*A(x)^3 = B(x*A(x^3)) where B(x) = x/(1 - 3*x).at n=11A091190
• Expansion of (1-x)/(1-2x+6x^2).at n=11A138229
• Number of solutions to +-1 +- 3 +- 6 +- ... +- n(n+1)/2 = 0.at n=24A158380
• Triangle read by rows: T(n,k) is the number of ordered trees with n edges and having k vertices of outdegree 2 that have (two) leaves as their (two) children.at n=28A178519
• Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal, vertical or diagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 n X 2 array.at n=22A219810
• Numbers n such that A193232(n) is a triangular number.at n=13A220518
• E.g.f.: exp( x*(1 + exp(2*x)) ).at n=6A240165
• Number of Carlitz compositions of n with exactly four descents.at n=9A241694
• Number of (5+1) X (n+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.at n=31A250659
• Starts of runs of 3 consecutive positive negaFibonacci-Niven numbers (A331085).at n=39A331087
• a(n) = 6*a(n - 1) - 12*a(n - 2) + 8*a(n - 3) for n >= 5, a(0) = 1, a(1) = 7, a(2) = 24, a(3) = 70, a(4) = 193.at n=9A339254
• Number of solutions to +-1 +- 3 +- 6 +- 10 +- ... +- n*(n + 1)/2 = 0 or 1.at n=24A350287
• Number of subsets of {1..n} with all different first differences of elements.at n=21A364465
• Triangle read by rows: T(n,k) is the number of rooted ordered trees with node weights summing to n, where the root has weight 0, all internal nodes have weight 1, and leaf nodes have weights in {1,...,k}.at n=53A384685