A353316 Heinz numbers of integer partitions that have a fixed point but whose conjugate does not (counted by A118199).

4, 8, 16, 27, 32, 45, 54, 63, 64, 81, 90, 99, 108, 117, 126, 128, 135, 153, 162, 171, 180, 189, 198, 207, 216, 234, 243, 252, 256, 261, 270, 279, 297, 306, 324, 333, 342, 351, 360, 369, 378, 387, 396, 405, 414, 423, 432, 459, 468, 477, 486, 504, 512, 513, 522

Offset

1,1

Comments

A fixed point of a sequence y is an index y(i) = i. A fixed point of a partition is unique if it exists.

The Heinz number of a partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k). This gives a bijective correspondence between positive integers and integer partitions.

Links

Table of n, a(n) for n=1..55.

Example

The terms together with their prime indices begin:
    4: (1,1)
    8: (1,1,1)
   16: (1,1,1,1)
   27: (2,2,2)
   32: (1,1,1,1,1)
   45: (3,2,2)
   54: (2,2,2,1)
   63: (4,2,2)
   64: (1,1,1,1,1,1)
   81: (2,2,2,2)
   90: (3,2,2,1)
   99: (5,2,2)
  108: (2,2,2,1,1)
  117: (6,2,2)
  126: (4,2,2,1)
  128: (1,1,1,1,1,1,1)
For example, the partition (3,2,2,1) with Heinz number 90 has a fixed point at the second position, but its conjugate (4,3,1) has no fixed points, so 90 is in the sequence.

Mathematica

primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];
pq[y_]:=Length[Select[Range[Length[y]], #==y[[#]]&]];
conj[y_]:=If[Length[y]==0, y, Table[Length[Select[y, #>=k&]], {k, 1, Max[y]}]];
Select[Range[100], pq[Reverse[primeMS[#]]]>0&& pq[conj[Reverse[primeMS[#]]]]==0&]

Crossrefs

These partitions are counted by A118199.

Crank: A342192, A352873, A352874; counted by A064410, A064428, A001522.

A000700 counts self-conjugate partitions, ranked by A088902.

A056239 adds up prime indices, row sums of A112798 and A296150.

A115720/A115994 count partitions by their Durfee square, rank stat A257990.

A122111 represents partition conjugation using Heinz numbers.

A238352 counts reversed partitions by fixed points, rank statistic A352822.

A238394 counts reversed partitions without a fixed point, ranked by A352830.

A238395 counts reversed partitions with a fixed point, ranked by A352872.

A352826 ranks partitions w/o a fixed point, counted by A064428 (unproved).

A352827 ranks partitions with a fixed point, counted by A001522 (unproved).

Cf. A001222, A065770, A093641, A114088, A188674, A252464, A300788, A325163, A325169, A352831, A352828, A352829.

Sequence in context: A096296 A331243 A180861 * A068936 A345329 A349112

Adjacent sequences: A353313 A353314 A353315 * A353317 A353318 A353319

Keyword

nonn

Author

Gus Wiseman, May 15 2022

Status

approved