34680

Appears in sequences

• Almost-convex polygons of perimeter 2n on square lattice.at n=2A007222
• Specific heat coefficients for square lattice spin 2 Ising model.at n=26A010112
• First differences of (n+1)^5-n^5.at n=11A068236
• A Pell Jacobsthal product.at n=8A084169
• a(1)=1; thereafter, a(n+1) = 20*n^3 + 10*n.at n=12A101098
• a(n) = sigma_2(n)*Pell(n), where sigma_2(n) = A001157(n), the sum of squares of divisors of n.at n=7A204272
• Areas A of the triangles such that A, the sides and the three altitudes are integers.at n=34A210643
• Self-convolution of A013999.at n=7A227096
• Integer areas of integer-sided triangles where two sides are of square length.at n=22A232461
• a(n) = 30*n^2.at n=34A244636
• Number of (2+1) X (n+1) 0..1 arrays with nondecreasing min(x(i,j),x(i,j-1)) in the i direction and nondecreasing absolute value of x(i,j)-x(i-1,j) in the j direction.at n=9A250799
• Triangle read by rows: T(n,g) = number of general immersions of a circle with n crossings in a surface of arbitrary genus g (the circle is not oriented, the surface is oriented).at n=25A260848
• Numbers with binary expansion Sum_{k = 0..w} b_k * 2^k such that the polynomial Sum_{k = 0..w} (X+k)^2 * (-1)^b_k is constant.at n=35A337672
• E.g.f. A(x) satisfies A(x) = exp( x^2*A(x)^2 / (1 - x*A(x))^2 ).at n=6A387948