2123366400

Appears in sequences

• Successive numerators of Wallis's approximation to Pi/2 (unreduced).at n=12A001900
• Central factorial numbers: a(n) = 4^n * (n!)^2.at n=6A002454
• Row 2 of array in A288580.at n=12A092396
• Triangle read by rows: row n gives coefficients in expansion of Product_{i=1..n} (x - (2i)^2), highest powers first.at n=27A182867
• Triangle read by rows: coefficients in expansion of Q(n) = (x-n^2)*(x-(n-2)^2)*(x-(n-4)^2)*...*(x-(1 or 2)^2), highest powers first.at n=54A182971
• a(n) = n^2*(n-2)^2*(n-4)^2*...*(1 or 2)^2.at n=12A184877
• Number of ways to place n nonattacking bishops on an n X n toroidal board.at n=11A189790
• Irregular triangle T(n,m), denominators of coefficients in a power/Fourier series expansion of the plane pendulum's exact time dependence.at n=27A274131