A350796 Number of unlabeled digraphs with n arcs and a global source and sink.
1, 1, 1, 2, 7, 25, 108, 513, 2690, 15230, 92361, 594669, 4040283, 28817783, 214898429, 1669663193, 13476692136, 112722792293, 974931812942, 8702563358405, 80039193725904, 757342429877879, 7362651015248190, 73451961108974776, 751144076656119144, 7866092802569673370
Offset: 0