70840

Appears in sequences

• Coefficient of x^4 in (1-x-x^2)^(-n).at n=31A006504
• From generalized Catalan numbers.at n=6A006631
• Number of different words that can be formed from an n X n grid of letters, reading horizontally, vertically or diagonally.at n=27A034720
• Triangle read by rows of numbers of paths in a lattice satisfying certain conditions.at n=51A071948
• Even numbers k such that the central binomial coefficient A000984(k, k/2) is divisible by k^2.at n=35A080395
• G.f.: Product_{m>=1} 1/(1-x^m)^32.at n=4A082557
• Triangle read by rows: T(n,k) is the number of noncrossing trees with root degree equal to k.at n=48A092276
• Number triangle T(n,k)=(-1)^(n-k)*(3k+2)*C(3n+1, n-k)/(2n+k+2).at n=38A124821
• a(n) = n*(n+1)*(n+2)*(n+3)/3.at n=20A162668
• Numbers that have 11 terms in their Zeckendorf representation.at n=30A179251
• Number of dissections of a convex (3n+3)-sided polygon into n pentagons and one triangle (up to equivalence).at n=6A185113
• Number of (n+1) X 2 0..1 arrays with column and row pair sums b(i,j)=a(i,j)+a(i,j-1) and c(i,j)=a(i,j)+a(i-1,j) nondecreasing in column and row directions, respectively.at n=18A204644
• Composite numbers m such that Sum_{i=1..k} (p_i/(p_i+1)) + Product_{i=1..k} (p_i/(p_i-1)) is an integer, where p_i are the k prime factors of m (with multiplicity).at n=24A230110
• Numbers of squares and rectangles of all sizes in 3*n*(n+1)/2-ominoes in form of three-quarters of Aztec diamonds.at n=21A338996
• G.f. satisfies A(x) = 1 + x^2*A(x)^4*(1 + x*A(x)).at n=13A365609