Number of equivalence classes of S_n under transformations of positionally and numerically adjacent elements of the form abc <--> acb <--> bac where a<b<c.
A212581
Number of equivalence classes of S_n under transformations of positionally and numerically adjacent elements of the form abc <--> acb <--> bac where a<b<c.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =17a(5) =89a(6) =556a(7) =4011a(8) =32843a(9) =301210a(10) =3059625a(11) =34104275a(12) =413919214a(13) =5434093341a(14) =76734218273
External references
- oeis: A212581