A116864 Array of product of parts of the partitions of n with only prime parts.

0, 2, 0, 3, 0, 0, 0, 0, 4, 0, 0, 5, 0, 6, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, 8, 0, 0, 0, 0, 7, 0, 10, 0, 0, 0, 0, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 15, 0, 0, 0, 0, 0, 18, 0, 0, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0, 0, 0, 14, 0, 0, 0, 0, 0, 0, 20, 0, 27

Offset

1,2

Comments

The inverse of sequence A001414 (sopfr(n)=sum of prime factors of n). See the examples and the W. Lang link.

The row length sequence of this array is p(n)=A000041(n) (number of partitions).

The partitions of n are ordered according to Abramowitz-Stegun (A-St), pp. 831-2.

Row n gives the values k for which A001414(k)=n>=2. E.g. n=10 appears 5 times in A001414, namely for the k values 21, 25, 30, 36 and 32.

Links

Table of n, a(n) for n=1..78.

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972.

W. Lang: First 10 rows.

Formula

a(n,k)=product(part(i),i=1..m(n,k)) if the k-th partition of n in the A-St order has only prime parts. Here m(n,k) is the number of parts of this partition. Otherwise a(n,k)=0. See A000040 for the prime numbers.

Example

[0];
[2, 0];
[3, 0, 0];
[0, 0, 4, 0, 0];
[5, 0, 6, 0, 0, 0, 0];
...
a(4,3)=4 because the third partition of 4 is, in A-St order, (2,2)
with product 4. There is only this partition of 4 with only prime parts.
Row n=5 shows: n=5 appears twice in A001414(k), namely for k= 5 and
6. This is related to the two partitions (5) and (3,2) with only prime parts.

Crossrefs

Row sums give A002098(n), n>=1.

Row sums (with nonzero numbers replaced by 1) give A000607(n), n>=1. See the array A116865.

Sequence in context: A013372 A209640 A080300 * A255308 A079302 A138806

Adjacent sequences: A116861 A116862 A116863 * A116865 A116866 A116867

Keyword

nonn,easy,tabf

Author

Wolfdieter Lang, Mar 24 2006

Status

approved