A358170 Heinz number of the partial sums of the n-th composition in standard order (A066099).

1, 2, 3, 6, 5, 15, 10, 30, 7, 35, 21, 105, 14, 70, 42, 210, 11, 77, 55, 385, 33, 231, 165, 1155, 22, 154, 110, 770, 66, 462, 330, 2310, 13, 143, 91, 1001, 65, 715, 455, 5005, 39, 429, 273, 3003, 195, 2145, 1365, 15015, 26, 286, 182, 2002, 130, 1430, 910, 10010

Offset

0,2

Comments

The k-th composition in standard order (graded reverse-lexicographic, A066099) is obtained by taking the set of positions of 1's in the reversed binary expansion of k, prepending 0, taking first differences, and reversing again. This gives a bijective correspondence between nonnegative integers and integer compositions.

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=0..55.

Gus Wiseman, Statistics, classes, and transformations of standard compositions

Example

The terms together with their prime indices begin:
           1: {}
           2: {1}
           3: {2}
           6: {1,2}
           5: {3}
          15: {2,3}
          10: {1,3}
          30: {1,2,3}
           7: {4}
          35: {3,4}
          21: {2,4}
         105: {2,3,4}
          14: {1,4}
          70: {1,3,4}
          42: {1,2,4}
         210: {1,2,3,4}

Mathematica

stc[n_]:=Differences[Prepend[Join @@ Position[Reverse[IntegerDigits[n, 2]], 1], 0]]//Reverse;
Times@@Prime/@#&/@Table[Accumulate[stc[n]], {n, 0, 100}]

Crossrefs

See link for sequences related to standard compositions.

Applying A001221 or A001222 gives A000120.

The image is A005117 (squarefree numbers).

The reverse version is A019565, triangular version A048793.

Greatest prime index of a(n) is A029837 or A070939.

Least prime index of a(n) is A065120.

The adjusted version is A253565, inverse A253566, reverse A005940.

These are the Heinz numbers of the rows of A358134.

Sum of prime indices of a(n) is A359042.

A066099 lists standard compositions.

A112798 list prime indices, sum A056239.

Cf. A000720, A001511, A029931, A059893, A061395, A241916, A242628, A355536, A358133, A358135, A358137.

Sequence in context: A066449 A276942 A255483 * A098012 A066117 A222311

Adjacent sequences: A358167 A358168 A358169 * A358171 A358172 A358173

Keyword

nonn

Author

Gus Wiseman, Dec 20 2022

Status

approved