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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.

A336107 Number of permutations of the prime indices of n with at least one non-singleton run, or non-separations.

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%I A336107 #11 Sep 17 2020 20:33:07
%S A336107 0,0,0,1,0,0,0,1,1,0,0,2,0,0,0,1,0,2,0,2,0,0,0,4,1,0,1,2,0,0,0,1,0,0,
%T A336107 0,4,0,0,0,4,0,0,0,2,2,0,0,5,1,2,0,2,0,4,0,4,0,0,0,6,0,0,2,1,0,0,0,2,
%U A336107 0,0,0,9,0,0,2,2,0,0,0,5,1,0,0,6,0,0,0
%N A336107 Number of permutations of the prime indices of n with at least one non-singleton run, or non-separations.
%C A336107 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 A336107 A separation (or Carlitz composition) of a multiset is a permutation with no adjacent equal parts.
%F A336107 a(n) = A008480(n) - A335452(n).
%F A336107 a(A000961(n)) = 0 if n is in A027883, otherwise 1.
%F A336107 a(A005117(n)) = 0.
%F A336107 a(n!) = A335459(n).
%F A336107 a(A006939(n)) = A022915(n).
%e A336107 The a(n) non-separations for n = 12, 36, 60, 72, 180, 420:
%e A336107   (11)  (112)  (1122)  (1123)  (11122)  (11223)  (11234)
%e A336107         (211)  (1221)  (1132)  (11212)  (11232)  (11243)
%e A336107                (2112)  (2113)  (11221)  (11322)  (11324)
%e A336107                (2211)  (2311)  (12112)  (12213)  (11342)
%e A336107                        (3112)  (12211)  (12231)  (11423)
%e A336107                        (3211)  (21112)  (13122)  (11432)
%e A336107                                (21121)  (13221)  (21134)
%e A336107                                (21211)  (21123)  (21143)
%e A336107                                (22111)  (21132)  (23114)
%e A336107                                         (22113)  (23411)
%e A336107                                         (22131)  (24113)
%e A336107                                         (22311)  (24311)
%e A336107                                         (23112)  (31124)
%e A336107                                         (23211)  (31142)
%e A336107                                         (31122)  (32114)
%e A336107                                         (31221)  (32411)
%e A336107                                         (32112)  (34112)
%e A336107                                         (32211)  (34211)
%e A336107                                                  (41123)
%e A336107                                                  (41132)
%e A336107                                                  (42113)
%e A336107                                                  (42311)
%e A336107                                                  (43112)
%e A336107                                                  (43211)
%t A336107 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
%t A336107 Table[Length[Select[Permutations[primeMS[n]],MatchQ[#,{___,x_,x_,___}]&]],{n,100}]
%Y A336107 A005117 lists positions of zeros, with complement A013929.
%Y A336107 A008480 counts permutations of prime indices, ranked by A333221.
%Y A336107 A003242 and A335452 count separations, ranked by A333489.
%Y A336107 A325535 counts inseparable partitions, ranked by A335448.
%Y A336107 A325534 counts separable partitions, ranked by A335433.
%Y A336107 Cf. A056239, A112798, A261962, A335451, A335452, A335460, A335489.
%K A336107 nonn
%O A336107 1,12
%A A336107 _Gus Wiseman_, Sep 03 2020