The number of sum indecomposable permutations which avoid the patterns 3124 and 4312.
A228770
The number of sum indecomposable permutations which avoid the patterns 3124 and 4312.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =12a(4) =51a(5) =217a(6) =912a(7) =3785a(8) =15554a(9) =63458a(10) =257566a(11) =1041548a(12) =4200462a(13) =16906262a(14) =67943341a(15) =272740788a(16) =1093881967a(17) =4384217569a(18) =17562176283a(19) =70319782015a(20) =281466691159
External references
- oeis: A228770