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.

A347637 Table read by ascending antidiagonals. T(n, k) is the minimum number of pebbles such that any assignment of those pebbles on a complete graph with n vertices is a next-player winning game in the two-player impartial (k+1, k) pebbling game. T(n, k) for n >= 5 and k >= 1.

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%I A347637 #36 Jun 28 2024 01:28:32
%S A347637 7,13,15,9,21,21,15,17,35,27,11,25,25,37,33,17,21,41,33,59,39,13,29,
%T A347637 31,45,41,53
%N A347637 Table read by ascending antidiagonals. T(n, k) is the minimum number of pebbles such that any assignment of those pebbles on a complete graph with n vertices is a next-player winning game in the two-player impartial (k+1, k) pebbling game. T(n, k) for n >= 5 and k >= 1.
%C A347637 A (k+1, k) pebbling move involves removing k + 1 pebbles from a vertex in a simple graph and placing k pebbles on an adjacent vertex.
%C A347637 A two-player impartial (k+1, k) pebbling game involves two players alternating (k+1, k) pebbling moves. The first player unable to make a move loses.
%C A347637 T(3, k) = A016921(k) for k >= 0. The proof will appear in a paper that is currently in preparation.
%C A347637 It is conjectured that T(4, k) for odd k>=3 is infinite, so we start with n = 5.
%C A347637 T(5, k) = A346197(k) for k >= 1.
%C A347637 T(n, 1) = A340631(n) for n >= 3.
%C A347637 T(n, 2) = A346401(n) for n >= 3.
%D A347637 E. R. Berlekamp, J. H. Conway, and R. K. Guy, Winning Ways for Your Mathematical Plays, Vol. 1, CRC Press, 2001.
%H A347637 Kayla Barker, Mia DeStefano, Eugene Fiorini, Michael Gohn, Joe Miller, Jacob Roeder, and Tony W. H. Wong, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL27/Wong/wong43.html">Generalized Impartial Two-player Pebbling Games on K_3 and C_4</a>, J. Int. Seq. (2024) Vol. 27, Issue 5, Art. No. 24.5.8. See p. 4.
%H A347637 Eugene Fiorini, Max Lind, Andrew Woldar, and Tony W. H. Wong, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL24/Wong/wong31.html">Characterizing Winning Positions in the Impartial Two-Player Pebbling Game on Complete Graphs</a>, J. Int. Seq., Vol. 24 (2021), Article 21.6.4.
%e A347637 The data is organized in a table beginning with row n = 5 and column k = 1. The data is read by ascending antidiagonals. The formula binomial(n + k - 5, 2) + k converts the indices from table form to sequence form.
%e A347637 The table T(n, k) begins:
%e A347637   [n/k]  1   2   3   4   5   6  ...
%e A347637   ---------------------------------
%e A347637   [ 5]   7, 15, 21, 27, 33, 39, ...
%e A347637   [ 6]  13, 21, 35, 37, 59, 53, ...
%e A347637   [ 7]   9, 17, 25, 33, 41, 51, ...
%e A347637   [ 8]  15, 25, 41, 45, 61, ...
%e A347637   [ 9]  11, 21, 31, 41, 51, ...
%e A347637   [10]  17, 29, 45, 53, 71, ...
%e A347637   [11]  13, 25, 37, 49, 61, ...
%e A347637   [12]  19, 33, 51, ...
%e A347637   [13]  15, 29, 43, ...
%e A347637   [14]  21, 37, ...
%e A347637   [15]  17, 33, ...
%e A347637   [16]  23, 41, ...
%t A347637 (* m represents number of vertices in the complete graph. Each pebbling move removes k+1 pebbles from a vertex and adds k pebbles to an adjacent vertex. *)
%t A347637 Do[(* Given m and a, list all possible assignments with a pebbles. *)
%t A347637 alltuples[m_, a_] := IntegerPartitions[a + m, {m}] - 1;
%t A347637 (* Given an assignment, list all resultant assignments after one pebbling move; only works for m>=3. *)
%t A347637 pebblemoves[config_] :=
%t A347637   Block[{m, temp}, m = Length[config];
%t A347637    temp = Table[config, {i, m (m - 1)}] +
%t A347637      Permutations[Join[{-(k + 1), k}, Table[0, {i, m - 2}]]];
%t A347637    temp = Select[temp, Min[#] >= 0 &];
%t A347637    temp = ReverseSort[DeleteDuplicates[ReverseSort /@ temp]]];
%t A347637 (* Given m and a, list all assignments that are P-games. *)
%t A347637 Plist = {};
%t A347637 plist[m_, a_] :=
%t A347637   Block[{index, tuples},
%t A347637    While[Length[Plist] < m, index = Length[Plist];
%t A347637     AppendTo[Plist, {{Join[{1}, Table[0, {i, index}]]}}]];
%t A347637    Do[AppendTo[Plist[[m]], {}]; tuples = alltuples[m, i];
%t A347637     Do[If[
%t A347637       Not[IntersectingQ[pebblemoves[tuples[[j]]],
%t A347637         If[i > 2, Plist[[m, i - 1]], {}]]],
%t A347637       AppendTo[Plist[[m, i]], tuples[[j]]]], {j, Length[tuples]}], {i,
%t A347637       Length[Plist[[m]]] + 1, a}]; Plist[[m, a]]];
%t A347637 (* Given m, print out the minimum a such that there are no P-games with a pebbles *)
%t A347637 Do[a = 1; While[plist[m, a] != {}, a++];
%t A347637   Print["k=", k, " m=", m, " a=", a], {m, 5, 10}], {k, 1, 6}]
%Y A347637 Cf. A340631, A346197, A346401.
%K A347637 nonn,more,tabl
%O A347637 5,1
%A A347637 _Kayla Barker_, _Mia DeStefano_, _Eugene Fiorini_, _Michael Gohn_, _Joe Miller_, _Jacob Roeder_, _Wing Hong Tony Wong_, Sep 09 2021