139350

Appears in sequences

• Total number of line segments between points visible to each other in a square n X n lattice.at n=25A141255
• Triangle read by rows, T(n, k) = binomial(n, k)*hypergeom([k-n, n+1], [k+2], -4), for n >= 0 and 0 <= k <= n.at n=40A297899
• Bisection of main diagonal of A115009.at n=12A358297
• G.f. A(x) satisfies A(x)/(1 + A(x)) = -A(x^3)/A(-x^2).at n=23A389429