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Number of labeled clutters (connected antichains) spanning some subset of {1,...,n} with singleton edges allowed.
7

%I #7 May 23 2018 23:13:08

%S 1,2,7,56,1533,210302,496838435,309068803876372,

%T 14369391923126181310256825

%N Number of labeled clutters (connected antichains) spanning some subset of {1,...,n} with singleton edges allowed.

%F Binomial transform of A304985(n > 0).

%e The a(2) = 7 clutters:

%e {}

%e {{1}}

%e {{2}}

%e {{1,2}}

%e {{1},{1,2}}

%e {{2},{1,2}}

%e {{1},{2},{1,2}}

%Y Cf. A048143, A198085, A261006, A304912, A304981, A304982, A304983, A304984, A304985, A304986.

%K nonn

%O 0,2

%A _Gus Wiseman_, May 23 2018