A054932 Number of unlabeled connected digraphs up to complementarity.
1, 1, 7, 95, 4628, 760731, 439476534, 895794710762, 6512183359880844, 170617184427498641390, 16261113406024864291983616, 5683340191820651519596089554647, 7334531479545984537334675978032833750, 35157813638509073199087893774184443496308877
Offset: 1
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..50
- V. A. Liskovets, Some easily derivable sequences, J. Integer Sequences, 3 (2000), #00.2.2.
Programs
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Maple
A054932 := proc(n) A003085(n)-(A000273(n)-A003086(n))/2 ; end proc: seq(A054932(n),n=1..13) ; # R. J. Mathar, Mar 04 2018
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Mathematica
A000273 = Cases[Import["https://oeis.org/A000273/b000273.txt", "Table"], {, }][[All, 2]]; A003085 = Cases[Import["https://oeis.org/A003085/b003085.txt", "Table"], {, }][[All, 2]]; A003086 = Cases[Import["https://oeis.org/A003086/b003086.txt", "Table"], {, }][[All, 2]]; a[n_] := A003085[[n]] - (A000273[[n + 1]] - A003086[[n]])/2; Array[a, 50] (* Jean-François Alcover, Sep 01 2019 *)
Formula
Extensions
Terms a(14) and beyond from Andrew Howroyd, Sep 17 2018