n-th Bell number of type D: Number of symmetric partitions of {-n,...,n}\{0} such that none of the subsets is of the form {j,-j}.

A086365

n-th Bell number of type D: Number of symmetric partitions of {-n,...,n}\{0} such that none of the subsets is of the form {j,-j}.

Terms

    a(0) =1a(1) =4a(2) =15a(3) =75a(4) =428a(5) =2781a(6) =20093a(7) =159340a(8) =1372163a(9) =12725447a(10) =126238060a(11) =1332071241a(12) =14881206473a(13) =175297058228

External references