Number of ordered set partitions of [n] into four blocks such that equal-sized blocks are ordered with increasing least elements.
A285919
Number of ordered set partitions of [n] into four blocks such that equal-sized blocks are ordered with increasing least elements.
Terms
- a(0) =1a(1) =40a(2) =350a(3) =3080a(4) =17129a(5) =82488a(6) =464650a(7) =1901680a(8) =8357426a(9) =35701952a(10) =159721016a(11) =627687060a(12) =2642405289a(13) =10712590392a(14) =45568675202a(15) =178738923440a(16) =736145997686
External references
- oeis: A285919