A334435 - OEIS

A334435

Heinz numbers of all reversed integer partitions sorted first by sum, then by length, and finally reverse-lexicographically.

1, 2, 3, 4, 5, 6, 8, 7, 9, 10, 12, 16, 11, 15, 14, 18, 20, 24, 32, 13, 25, 21, 22, 27, 30, 28, 36, 40, 48, 64, 17, 35, 33, 26, 45, 50, 42, 44, 54, 60, 56, 72, 80, 96, 128, 19, 49, 55, 39, 34, 75, 63, 70, 66, 52, 81, 90, 100, 84, 88, 108, 120, 112, 144, 160, 192, 256

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OFFSET

0,2

COMMENTS

First differs from A334433 at a(75) = 99, A334433(75) = 98.

First differs from A334436 at a(22) = 22, A334436(22) = 27.

A permutation of the positive integers.

Reversed integer partitions are finite weakly increasing sequences of positive integers.

This is the Abramowitz-Stegun ordering of reversed partitions (A185974) except that the finer order is reverse-lexicographic instead of lexicographic. The version for non-reversed partitions is A334438.

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

As a triangle with row lengths A000041, the sequence starts {{1},{2},{3,4},{5,6,8},...}, so offset is 0.

LINKS

Table of n, a(n) for n=0..66.

Wikiversity, Lexicographic and colexicographic order

FORMULA

A001222(a(n)) = A036043(n).

EXAMPLE

The sequence of terms together with their prime indices begins:

1: {} 32: {1,1,1,1,1} 42: {1,2,4}

2: {1} 13: {6} 44: {1,1,5}

3: {2} 25: {3,3} 54: {1,2,2,2}

4: {1,1} 21: {2,4} 60: {1,1,2,3}

5: {3} 22: {1,5} 56: {1,1,1,4}

6: {1,2} 27: {2,2,2} 72: {1,1,1,2,2}

8: {1,1,1} 30: {1,2,3} 80: {1,1,1,1,3}

7: {4} 28: {1,1,4} 96: {1,1,1,1,1,2}

9: {2,2} 36: {1,1,2,2} 128: {1,1,1,1,1,1,1}

10: {1,3} 40: {1,1,1,3} 19: {8}

12: {1,1,2} 48: {1,1,1,1,2} 49: {4,4}

16: {1,1,1,1} 64: {1,1,1,1,1,1} 55: {3,5}

11: {5} 17: {7} 39: {2,6}

15: {2,3} 35: {3,4} 34: {1,7}

14: {1,4} 33: {2,5} 75: {2,3,3}

18: {1,2,2} 26: {1,6} 63: {2,2,4}

20: {1,1,3} 45: {2,2,3} 70: {1,3,4}

24: {1,1,1,2} 50: {1,3,3} 66: {1,2,5}

Triangle begins:

3 4

5 6 8

7 9 10 12 16

11 15 14 18 20 24 32

13 25 21 22 27 30 28 36 40 48 64

17 35 33 26 45 50 42 44 54 60 56 72 80 96 128

This corresponds to the following tetrangle:

(1)

(2)(11)

(3)(12)(111)

(4)(22)(13)(112)(1111)

(5)(23)(14)(122)(113)(1112)(11111)

MATHEMATICA

revlensort[f_, c_]:=If[Length[f]!=Length[c], Length[f]<Length[c], OrderedQ[{c, f}]];

Table[Times@@Prime/@#&/@Sort[Sort/@IntegerPartitions[n], revlensort], {n, 0, 8}]

CROSSREFS

Row lengths are A000041.

The dual version (sum/length/lex) is A185974.

Compositions under the same order are A296774 (triangle).

The constructive version is A334302.

Ignoring length gives A334436.

The version for non-reversed partitions is A334438.

Partitions in this order (sum/length/revlex) are A334439.

Lexicographically ordered reversed partitions are A026791.

Reversed partitions in Abramowitz-Stegun (sum/length/lex) order are A036036.

Partitions in increasing-length colex order (sum/length/colex) are A036037.

Reverse-lexicographically ordered partitions are A080577.

Sorting reversed partitions by Heinz number gives A112798.

Graded lexicographically ordered partitions are A193073.

Partitions in colexicographic (sum/colex) order are A211992.

Graded Heinz numbers are given by A215366.

Sorting partitions by Heinz number gives A296150.

Cf. A056239, A124734, A129129, A228100, A228531, A333219, A333220, A334301, A334433, A334434, A334437.

Sequence in context: A215366 A333483 A334433 * A334436 A266195 A102530

Adjacent sequences: A334432 A334433 A334434 * A334436 A334437 A334438

KEYWORD

nonn,tabf

AUTHOR

Gus Wiseman, May 02 2020

STATUS

approved