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.

A262671 Number of pointed multiset partitions of normal pointed multisets of weight n.

This page as a plain text file.
%I A262671 #14 Aug 26 2016 16:55:01
%S A262671 1,6,42,335,2956,28468,296540
%N A262671 Number of pointed multiset partitions of normal pointed multisets of weight n.
%C A262671 A pointed multiset k[1...k...n] with point k is normal if its entries [1...k...n] span an initial interval of positive integers. Pointed multiset partitions are triangles (or compositions) in the multiorder of pointed multisets.
%H A262671 Gus Wiseman, <a href="https://docs.google.com/document/d/1m0s6DGTBkDW9gvMuFmJHvy6oLGRAbQ7okAZcOPZawp0/pub">Comcategories and Multiorders</a>
%e A262671 The a(2) = 6 pointed multiset partitions are:
%e A262671 1[1[11]],1[1[1]1[1]],
%e A262671 1[1[12]],1[1[1]2[2]],
%e A262671 2[2[12]],2[1[1]2[2]].
%e A262671 The a(3) = 42 pointed multiset partitions are:
%e A262671 1[1[111]],1[1[1]1[11]],1[1[11]1[1]],1[1[1]1[1]1[1]],
%e A262671 1[1[122]],1[1[1]2[22]],1[1[12]2[2]],1[1[1]2[2]2[2]],
%e A262671 2[2[122]],2[1[1]2[22]],2[1[12]2[2]],2[2[2]2[12]],2[2[12]2[2]],2[1[1]2[2]2[2]],
%e A262671 1[1[112]],1[1[1]1[12]],1[1[1]2[12]],1[1[11]2[2]],1[1[12]1[1]],1[1[1]1[1]2[2]],
%e A262671 2[2[112]],2[1[1]2[12]],2[1[11]2[2]],2[1[1]1[1]2[2]],
%e A262671 1[1[123]],1[1[1]2[23]],1[1[1]3[23]],1[1[12]3[3]],1[1[13]2[2]],1[1[1]2[2]3[3]],
%e A262671 2[2[123]],2[1[1]2[23]],2[1[13]2[2]],2[2[2]3[13]],2[2[12]3[3]],2[1[1]2[2]3[3]],
%e A262671 3[3[123]],3[1[1]3[23]],3[1[12]3[3]],3[2[2]3[13]],3[2[12]3[3]],3[1[1]2[2]3[3]].
%t A262671 ReplaceListRepeated[forms_List, rerules_List] :=
%t A262671 Union[Flatten[
%t A262671    FixedPointList[
%t A262671     Function[preforms,
%t A262671      Union[Flatten[ReplaceList[#, rerules] & /@ preforms, 1]]],
%t A262671     forms], 1]]
%t A262671 pointedPartitions[JIX[r_, b_List?OrderedQ]] /; MemberQ[b, r] :=
%t A262671   Cases[ReplaceListRepeated[{Z[Y[JIX[r, {r}]],
%t A262671       Y @@ DeleteCases[b, r, 1, 1]]}, {Z[Y[sof___, JIX[w_, t_]],
%t A262671         Y[for___, x_, aft___]] /; OrderedQ[{w, x}] :>
%t A262671       Z[Y[sof, JIX[w, t], JIX[x, {x}]], Y[for, aft]],
%t A262671      Z[Y[JIX[w_, t_], soa___], Y[for___, x_, aft___]] /;
%t A262671        OrderedQ[{x, w}] :>
%t A262671       Z[Y[JIX[x, {x}], JIX[w, t], soa], Y[for, aft]],
%t A262671      Z[Y[sof___, JIX[w_, {tof__}]], Y[for___, x_, aft___]] :>
%t A262671       Z[Y[sof, JIX[w, Sort[{tof, x}]]], Y[for, aft]],
%t A262671      Z[Y[JIX[w_, {tof__}], soa___], Y[for___, x_, aft___]] :>
%t A262671       Z[Y[JIX[w, Sort[{tof, x}]], soa], Y[for, aft]]}],
%t A262671    Z[Y[pts__], Y[]] :> JIX[r, {pts}]];
%t A262671 allnormpms[n_Integer] :=
%t A262671   Join @@ Function[s,
%t A262671      JIX[#, Array[Count[s, y_ /; y <= #] + 1 &, n]] & /@
%t A262671       Range[Length[s] + 1]] /@ Subsets[Range[n - 1] + 1];
%t A262671 Join @@ pointedPartitions /@ allnormpms[3] /.
%t A262671 JIX -> Apply(* to construct the example *)
%t A262671 Array[Plus @@ (Length[pointedPartitions[#]] & /@
%t A262671      allnormpms[#]) &, 7](* to compute the sequence *)
%Y A262671 Cf. A185298, A080108, A276024.
%K A262671 nonn,more
%O A262671 1,2
%A A262671 _Gus Wiseman_, Sep 26 2015