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.

A300384 In the ranked poset of integer partitions ordered by refinement, number of maximal chains from the local minimum to the partition with Heinz number n.

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%I A300384 #5 Mar 04 2018 23:17:37
%S A300384 0,1,1,1,1,1,2,1,1,1,4,1,11,2,2,1,33,1,116,1,5,4,435,1,2,11,1,2,1832,
%T A300384 2,8167,1,12,33,10,1,39700,116,37,1,201785,5,1099449,4,3,435,6237505,
%U A300384 1,19,2,123,11,37406458,1,27,2,474,1832,232176847,2,1513796040
%N A300384 In the ranked poset of integer partitions ordered by refinement, number of maximal chains from the local minimum to the partition with Heinz number n.
%C A300384 The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k).
%e A300384 The a(21) = 5 maximal chains are the rows:
%e A300384 (111111)<(21111)<(2211)<(222)<(42)
%e A300384 (111111)<(21111)<(2211)<(411)<(42)
%e A300384 (111111)<(21111)<(2211)<(321)<(42)
%e A300384 (111111)<(21111)<(3111)<(411)<(42)
%e A300384 (111111)<(21111)<(3111)<(321)<(42)
%t A300384 pcovs[ptn_]:=Select[Union[Reverse/@Sort/@Join@@@Tuples[IntegerPartitions/@ptn]],Length[#]===Length[ptn]+1&];
%t A300384 coc[ptn_]:=coc[ptn]=If[Max[ptn]===1,1,Total[coc/@pcovs[ptn]]];
%t A300384 primeMS[n_]:=If[n===1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
%t A300384 Table[coc[Reverse[primeMS[n]]],{n,50}]
%Y A300384 Cf. A000041, A001055, A001222, A002846, A056239, A112798, A213427, A215366, A265947, A296150, A299200, A299202, A299925, A300273, A300383, A300385.
%K A300384 nonn
%O A300384 1,7
%A A300384 _Gus Wiseman_, Mar 04 2018