If X_1,...,X_n is a partition of a 2n-set X into 2-blocks then a(n) is equal to the number of 6-subsets of X containing none of X_i, (i=1,...n).

A130812

If X_1,...,X_n is a partition of a 2n-set X into 2-blocks then a(n) is equal to the number of 6-subsets of X containing none of X_i, (i=1,...n).

Terms

    a(0) =64a(1) =448a(2) =1792a(3) =5376a(4) =13440a(5) =29568a(6) =59136a(7) =109824a(8) =192192a(9) =320320a(10) =512512a(11) =792064a(12) =1188096a(13) =1736448a(14) =2480640a(15) =3472896a(16) =4775232a(17) =6460608a(18) =8614144a(19) =11334400a(20) =14734720a(21) =18944640a(22) =24111360a(23) =30401280a(24) =38001600a(25) =47121984a(26) =57996288a(27) =70884352a(28) =86073856a(29) =103882240

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