26260

Appears in sequences

• Alternate partial sums of binomial(3n,n)^2/(2n+1).at n=4A188683
• Number of (w,x,y) with all terms in {0,...,n} and w != x and x < range(w,x,y).at n=39A212970
• a(0) = 0 by convention; for n>0, a(n) is the number of edges in the n-th figure shown in A255011 (meaning the figure with 4n points on the perimeter).at n=7A331448
• Triangle read by rows: T(n,m) (n >= m >= 1) = number of line segments formed by drawing the lines connecting any two of the 2*(m+n) perimeter points of an m X n grid of squares.at n=27A331454
• Number of unlabeled 3-connected graphs with n edges.at n=12A338511
• Number of integer partitions of n with no adjacent parts having quotient > 2.at n=44A342094
• Expansion of Sum_{k>0} x^(4*k)/(1+x^k)^5.at n=29A363618
• Table read by antidiagonals: Place k equally spaced points on each side of a regular n-gon and join every pair of the n*(k+1) boundary points by a chord; T(n,k) (n >= 3, k >= 0) gives the number of edges in the resulting planar graph.at n=29A367324
• Antichain-Chain Quilt Numbers: Square table of the number of ASM quilts of type A_2(j) x C_k read down antidiagonals, where C_k is the chain poset or rank k and A_2(j) is the rank 2 poset with a unique minimal and maximal element and j atoms.at n=49A374822