The number of evenly tagged partitions: partitions of n elements together with an involution defined on the set of classes which has at most one fixed point, such that a class and its image have the same number of elements.
A355194
The number of evenly tagged partitions: partitions of n elements together with an involution defined on the set of classes which has at most one fixed point, such that a class and its image have the same number of elements.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =13a(5) =41a(6) =176a(7) =722a(8) =3774a(9) =18958a(10) =116302a(11) =687182a(12) =4812226a(13) =32541874a(14) =255274826a(15) =1938568634a(16) =16798483589a(17) =141220228149
External references
- oeis: A355194