Number of permutations of 2 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/4)] (4-way heap).
A178014
Number of permutations of 2 copies of 1..n with no element e[i>=2]<e[1+floor((i-2)/4)] (4-way heap).
Terms
- a(0) =1a(1) =3a(2) =18a(3) =189a(4) =3000a(5) =84060a(6) =2799360a(7) =148771080a(8) =8457799680a(9) =727583990400
External references
- oeis: A178014