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A350906
Number of unlabeled initially-finally connected digraphs with n arcs.
4
1, 1, 2, 5, 16, 56, 241, 1111, 5748, 31912, 190328, 1204317, 8050341, 56516303, 415128256, 3179020729, 25308005049, 208918893640, 1784451646305, 15739926014382, 143130061546156, 1339761466105929, 12891329514544223, 127351374611721837, 1290198076415425548, 13390893744153374776
OFFSET
0,3
PROG
(PARI) A350906seq(15) \\ See PARI link in A350794 for program code.
CROSSREFS
Column sums of A057278.
Cf. A049531 (by vertices), A350752, A350796, A350798, A350907.
Sequence in context: A352905 A052815 A195931 * A082789 A234278 A180678
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Jan 21 2022
STATUS
approved