A382913 Numbers k such that row k of A305936 (a multiset whose multiplicities are the prime indices of k) has a permutation with all distinct run-lengths.

1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 25, 26, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 46, 47, 49, 51, 53, 55, 57, 58, 59, 61, 62, 65, 66, 67, 69, 70, 71, 73, 74, 77, 78, 79, 82, 83, 85, 86, 87, 89, 91, 93, 94, 95, 97, 101, 102, 103

Offset

1,2

Comments

This described multiset (row n of A305936, Heinz number A181821) is generally not the same as the multiset of prime indices of n (A112798). 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}.

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, sum A056239.

Links

Table of n, a(n) for n=1..66.

Example

The terms, prime indices, and corresponding multisets begin:
   1:    {} {}
   2:   {1} {1}
   3:   {2} {1,1}
   5:   {3} {1,1,1}
   6: {1,2} {1,1,2}
   7:   {4} {1,1,1,1}
  10: {1,3} {1,1,1,2}
  11:   {5} {1,1,1,1,1}
  13:   {6} {1,1,1,1,1,1}
  14: {1,4} {1,1,1,1,2}
  15: {2,3} {1,1,1,2,2}
  17:   {7} {1,1,1,1,1,1,1}
  19:   {8} {1,1,1,1,1,1,1,1}
  21: {2,4} {1,1,1,1,2,2}
  22: {1,5} {1,1,1,1,1,2}
  23:   {9} {1,1,1,1,1,1,1,1,1}
  25: {3,3} {1,1,1,2,2,2}
  26: {1,6} {1,1,1,1,1,1,2}

Mathematica

nrmptn[n_]:=Join@@MapIndexed[Table[#2[[1]], {#1}]&, If[n==1, {}, Flatten[Cases[FactorInteger[n]//Reverse, {p_, k_} :> Table[PrimePi[p], {k}]]]]];
lasQ[y_]:=Select[Permutations[y], UnsameQ@@Length/@Split[#]&]!={};
Select[Range[100], lasQ@*nrmptn]

Crossrefs

Look-and-Say partitions are counted by A239455, ranks A351294.

Non-Look-and-Say partitions are counted by A351293, ranks A351295.

For prime indices instead of signature we have A351294, conjugate A381432.

The Look-and-Say partition of n is listed by A381440, rank A048767.

The complement is A382912.

For equal run-lengths we have the complement of A382914, see A382858, A382879, A382915.

A044813 lists numbers whose binary expansion has distinct run-lengths.

A055396 gives least prime index, greatest A061395.

A056239 adds up prime indices, row sums of A112798.

A329739 counts compositions with distinct run-lengths, ranks A351596.

A381431 ranks section-sum partition, listed by A381436.

Cf. A000720, A001221, A001222, A140690, A181821, A305936, A335125, A382525, A382771, A382773, A382775.

Cf. A381636, A381717, A381871, A382876.

Sequence in context: A064594 A325511 A387177 * A240370 A193304 A390440

Adjacent sequences: A382910 A382911 A382912 * A382914 A382915 A382916

Keyword

nonn

Author

Gus Wiseman, Apr 12 2025

Status

approved