Until recently, the number of non-separable graphs on seven or fewer points was known due to hand computations carried out by DeRocco . By implementing an algorithm of Robinson  on a digital computer we were able to compute the number of non-separable graphs on nine or fewer points. this paper presents these numbers.
Osterweil, Leon J., "Enumeration of Non-Separable Graphs on Fewer than Ten Points ; CU-CS-005-72" (1972). Computer Science Technical Reports. 5.