90576

Appears in sequences

• Expansion of (1-x)/(1 - x - 2*x^3 + x^4).at n=29A052916
• Maximal number of regions obtained by a straight line drawing of the complete bipartite graph K_{n,n}.at n=24A117717
• G.f.: A(x) = (A_1)^3 where A_1 = 1 + x*(A_2)^3; A_2 = 1 + x^2*(A_3)^3; A_3 = 1 + x^3*(A_4)^3; ... A_n = 1 + x^n*(A_{n+1})^3 for n>=1.at n=20A132331
• Triangle read by rows: a(n,k) is the number of k X n matrices which are the first k rows of an alternating sign matrix of size n.at n=49A297622