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 A300120 Number of skew partitions whose quotient diagram is connected and whose numerator has weight n. 7
 2, 6, 12, 26, 44, 86, 136, 239, 376, 613, 930, 1485, 2194, 3355, 4948, 7372, 10656, 15660, 22359, 32308 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The diagram of a connected skew partition is required to be connected as a polyomino but can have empty rows or columns. LINKS EXAMPLE The a(3) = 12 skew partitions: (3)/() (3)/(1) (3)/(2) (3)/(3) (21)/() (21)/(11) (21)/(2) (21)/(21) (111)/() (111)/(1) (111)/(11) (111)/(111) MATHEMATICA undcon[y_]:=Select[Tuples[Range[0, #]&/@y], Function[v, GreaterEqual@@v&&With[{r=Select[Range[Length[y]], y[[#]]=!=v[[#]]&]}, Or[Length[r]<=1, And@@Table[v[[i]]

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Last modified February 8 00:00 EST 2023. Contains 360133 sequences. (Running on oeis4.)