a(n) is n! times the coefficient of Pi^floor(n/2) in the volume of an n-dimensional unit ball.

A094941

a(n) is n! times the coefficient of Pi^floor(n/2) in the volume of an n-dimensional unit ball.

Terms

    a(0) =1a(1) =2a(2) =2a(3) =8a(4) =12a(5) =64a(6) =120a(7) =768a(8) =1680a(9) =12288a(10) =30240a(11) =245760a(12) =665280a(13) =5898240a(14) =17297280a(15) =165150720a(16) =518918400a(17) =5284823040a(18) =17643225600a(19) =190253629440a(20) =670442572800

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