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

A285918

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

Terms

    a(0) =1a(1) =18a(2) =75a(3) =420a(4) =1218a(5) =4242a(6) =14563a(7) =42930a(8) =132528a(9) =432960a(10) =1250340a(11) =3814629a(12) =12073701a(13) =35074482a(14) =106044555a(15) =331913202a(16) =967193328a(17) =2917846758a(18) =9062084298a(19) =26507831559a(20) =79848170823a(21) =246771097680a(22) =723922691700

External references