Number of permutations of 1..n with no element e[i>=2]<e[1+floor((i-2)/5)] (5-way heap).
A178010
Number of permutations of 1..n with no element e[i>=2]<e[1+floor((i-2)/5)] (5-way heap).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =6a(5) =24a(6) =120a(7) =360a(8) =1680a(9) =10080a(10) =72576a(11) =604800a(12) =3326400a(13) =26611200a(14) =259459200a(15) =2905943040a(16) =36324288000a(17) =290594304000
External references
- oeis: A178010