cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A373457 Number of losing integer partitions of n in the impartial combinatorial game LCTR (left column, top row).

Original entry on oeis.org

0, 0, 1, 3, 3, 4, 7, 11, 12, 17, 24, 34, 40, 54, 73, 100, 125, 164, 208, 270, 337, 428, 534, 673, 828, 1033, 1276, 1584, 1938, 2385, 2909, 3559, 4318, 5252, 6346, 7678, 9230, 11108, 13309, 15953, 19034, 22719, 27019, 32132, 38084, 45129, 53326, 62988, 74200, 87371
Offset: 1

Views

Author

Eric Gottlieb, Jun 06 2024

Keywords

Examples

			For n = 8, the a(8) = 11 losing partitions are the six nondegenerate hooks (7,1), (6, 1, 1), (5, 1, 1, 1), (4, 1, 1, 1, 1), (3, 1, 1, 1, 1, 1), (2, 1, 1, 1, 1, 1, 1) and (5, 3), (4, 4), (3, 3, 2), (2, 2, 2, 2), (2, 2, 2, 1, 1).
		

Crossrefs

Cf. A000041.

Programs

  • Mathematica
    << "Combinatorica`"
    Mex[Ls_] :=
     If[Ls == {}, 0, Min[Complement[Table[n, {n, 0, Length[Ls]}], Ls]]]
    LCTRMoves[Pttn_] :=
     Union[{Rest[Pttn],
       TransposePartition[Rest[TransposePartition[Pttn]]]}]
    LCTRSG[Pttn_] :=
     If[Pttn == {}, 0, LCTRSG[Pttn] = Mex[LCTRSG /@ LCTRMoves[Pttn]]]
    NumLosingPttns[n_] :=
     Table[{k,
        Length[Select[IntegerPartitions[k], LCTRSG[#] == 0 &]]}, {k, 1,
        n}] // TableForm