3880900

Appears in sequences

• Perfect squares using only the curved digits 0, 3, 6, 8 and 9.at n=27A079655
• Consider the sequence of circles C0, C1, C2, C3 ..., where C0 is a half-circle of radius 1. C1 is the largest circle that fits into C0 and has radius 1/2. C(n+1) is the largest circle that fits inside C0 but outside C(n), etc. Sequence gives the curvatures (reciprocals of the radii) of the circles.at n=9A099938
• Expansion of (1+2*x-2*x^3-3*x^2)/((x-1)*(x+1)*(x^2+2*x-1)).at n=17A100828
• Perfect squares (A000290) that can be expressed as the sum of four consecutive triangular numbers (A000217).at n=4A165518
• Twice A024537.at n=17A182780
• Number of 6Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 0 and 1 1 1 vertically.at n=11A209227
• Number of (n+2)X2 0..3 arrays with all rows having a nonnegative second derivative, and all and columns having a positive second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative.at n=3A223493
• T(n,k)=Number of (n+2)Xk 0..3 arrays with all rows having a nonnegative second derivative, and all and columns having a positive second derivative in a quadratic least squares fit, with one and two element arrays taken as having a zero second derivative.at n=13A223495