A352761 Number of partial order relations on [n] such that 1 and 2 are in the same connected component.

2, 14, 176, 3644, 117860, 5755964, 414823916, 43390462724, 6502296995300, 1380924739533644, 411744185101611356, 170949139294419110804, 98118349844314838731220, 77360523694460582654188124, 83319557470828626639253920716, 121980734453060653381753104078884, 241689591664023311258411470178766020

Offset: 2

Author

Geoffrey Critzer, Jul 05 2022

Keywords

• nonn

Crossrefs

Cf. A001035, A352399.

Programs

Mathematica

nn = 16; A[x_] := Total[Cases[Import["https://oeis.org/A001035/b001035.txt",
      "Table"], {, }][[All, 2]]*Table[x^(i - 1)/(i - 1)!, {i, 1, 19}]];
Range[0, nn]! CoefficientList[ Series[D[D[Log[A[x]], x], x] A[x], {x, 0, nn}], x]