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A335126 A multiset whose multiplicities are the prime indices of n is inseparable. 23

%I #9 Jul 03 2020 06:58:23

%S 3,5,7,10,11,13,14,17,19,21,22,23,26,28,29,31,33,34,37,38,39,41,43,44,

%T 46,47,51,52,53,55,57,58,59,61,62,65,66,67,68,69,71,73,74,76,78,79,82,

%U 83,85,86,87,88,89,91,92,93,94,95,97,101,102,103,104,106

%N A multiset whose multiplicities are the prime indices of n is inseparable.

%C A multiset is separable if it has a permutation that is an anti-run, meaning there are no adjacent equal parts.

%C A multiset whose multiplicities are the prime indices of n (such as row n of A305936) is not the same as the multiset of prime indices of n. For example, the prime indices of 12 are {1,1,2}, while a multiset whose multiplicities are {1,1,2} is {1,1,2,3}.

%e The sequence of terms together with the corresponding multisets begins:

%e 3: {1,1}

%e 5: {1,1,1}

%e 7: {1,1,1,1}

%e 10: {1,1,1,2}

%e 11: {1,1,1,1,1}

%e 13: {1,1,1,1,1,1}

%e 14: {1,1,1,1,2}

%e 17: {1,1,1,1,1,1,1}

%e 19: {1,1,1,1,1,1,1,1}

%e 21: {1,1,1,1,2,2}

%e 22: {1,1,1,1,1,2}

%e 23: {1,1,1,1,1,1,1,1,1}

%e 26: {1,1,1,1,1,1,2}

%e 28: {1,1,1,1,2,3}

%e 29: {1,1,1,1,1,1,1,1,1,1}

%t nrmptn[n_]:=Join@@MapIndexed[Table[#2[[1]],{#1}]&,If[n==1,{},Flatten[Cases[FactorInteger[n]//Reverse,{p_,k_}:>Table[PrimePi[p],{k}]]]]];

%t Select[Range[100],Select[Permutations[nrmptn[#]],!MatchQ[#,{___,x_,x_,___}]&]=={}&]

%Y The complement is A335127.

%Y Anti-run compositions are A003242.

%Y Anti-runs are ranked by A333489.

%Y Separable partitions are A325534.

%Y Inseparable partitions are A325535.

%Y Separable factorizations are A335434.

%Y Inseparable factorizations are A333487.

%Y Separable partitions are ranked by A335433.

%Y Inseparable partitions are ranked by A335448.

%Y Anti-run permutations of prime indices are A335452.

%Y Patterns contiguously matched by compositions are A335457.

%Y Cf. A025487, A056239, A106351, A112798, A114938, A181819, A181821, A278990, A292884, A335407, A335489, A335516, A335838.

%K nonn

%O 1,1

%A _Gus Wiseman_, Jul 01 2020

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Last modified August 18 01:44 EDT 2024. Contains 375255 sequences. (Running on oeis4.)