Number of ordered set partitions of [n] into two blocks such that equal-sized blocks are ordered with increasing least elements.

A285917

Number of ordered set partitions of [n] into two blocks such that equal-sized blocks are ordered with increasing least elements.

Terms

    a(0) =1a(1) =6a(2) =11a(3) =30a(4) =52a(5) =126a(6) =219a(7) =510a(8) =896a(9) =2046a(10) =3632a(11) =8190a(12) =14666a(13) =32766a(14) =59099a(15) =131070a(16) =237832a(17) =524286a(18) =956196a(19) =2097150a(20) =3841586a(21) =8388606a(22) =15425136a(23) =33554430a(24) =61908562a(25) =134217726a(26) =248377154a(27) =536870910a(28) =996183062a(29) =2147483646

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