%I #9 Jun 30 2020 01:55:07
%S 0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,4,0,0,1,0,0,0,0,1,0,0,
%T 0,0,0,0,0,4,0,0,0,0,0,0,0,5,0,0,0,0,0,4,0,4,0,0,0,0,0,0,0,1,0,0,0,0,
%U 0,0,0,10,0,0,0,0,0,0,0,5,1,0,0,0,0,0,0
%N Number of (1,1,1)-matching permutations of the prime indices of n.
%C A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.
%C We define a pattern to be a finite sequence covering an initial interval of positive integers. Patterns are counted by A000670 and ranked by A333217. A sequence S is said to match a pattern P if there is a not necessarily contiguous subsequence of S whose parts have the same relative order as P. For example, (3,1,1,3) matches (1,1,2), (2,1,1), and (2,1,2), but avoids (1,2,1), (1,2,2), and (2,2,1).
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Permutation_pattern">Permutation pattern</a>
%H Gus Wiseman, <a href="https://oeis.org/A102726/a102726.txt">Sequences counting and ranking compositions by the patterns they match or avoid.</a>
%F If n is cubefree, a(n) = 0; otherwise a(n) = A008480(n).
%t primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
%t Table[Length[Select[Permutations[primeMS[n]],MatchQ[#,{___,x_,___,x_,___,x_,___}]&]],{n,0,100}]
%Y Patterns matching this pattern are counted by A335508.
%Y These compositions are counted by A335455.
%Y The (1,1)-matching version is A335487.
%Y The complement A335511 is the avoiding version.
%Y These permutations are ranked by A335512.
%Y Permutations of prime indices are counted by A008480.
%Y Patterns are counted by A000670 and ranked by A333217.
%Y Anti-run permutations of prime indices are counted by A335452.
%Y Cf. A056239, A056986, A112798, A238279, A281188, A333221, A333755, A335456, A335460, A335462, A335463.
%K nonn
%O 1,24
%A _Gus Wiseman_, Jun 19 2020
|