-394404

Appears in sequences

• a(n) = P_n(-1), where P_n(x) is a certain polynomial arising in the enumeration of tatami mat coverings.at n=21A226302
• Coefficients of the minimal polynomials of the algebraic numbers sqLhat(2*l) from A230072, l >= 1, related to the square of all length in a regular (2*l)-gon inscribed in a circle of radius 1 length unit.at n=60A230073