A001374Number of relational systems on n nodes. Also number of directed 3-multigraphs with loops on n nodes.

4, 136, 44224, 179228736, 9383939974144, 6558936236286040064, 62879572771326489528942592, 8439543710699844562674685252214784, 16110027001555070629022725866559372785352704, 442829046878106126159584032189649757399796014050181120

The first term appear at position 2.

14159265358979323846264338…
position 2
termsstringfirst positionoccurrences
142100,011,958
241362,310100,653
3413644224not within 1,000,000,0000

Searched the first 1,000,000,000 digits. Strings longer than 12 digits are not indexed.