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A144357 Partition number array, called M31(-1), related to A049403(n,m)= S1(-1;n,m) (generalized Stirling triangle). 4
1, 1, 1, 0, 3, 1, 0, 0, 3, 6, 1, 0, 0, 0, 0, 15, 10, 1, 0, 0, 0, 0, 0, 0, 15, 0, 45, 15, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 105, 0, 105, 21, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 105, 0, 0, 420, 0, 210, 28, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 945, 0, 0, 1260, 0, 378, 36 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Each partition of n, ordered as in Abramowitz-Stegun (A-St order; for the reference see A134278), is mapped to a nonnegative integer a(n,k) =: M31(-1;n,k) with the k-th partition of n in A-St order.

The sequence of row lengths is A000041 (partition numbers) [1, 2, 3, 5, 7, 11, 15, 22, 30, 42,...].

First member (K=1) in the family M31(-K) of partition number arrays.

If M31(-1;n,k) is summed over those k with fixed number of parts m one obtains the unsigned triangle S1(-1):= A049403.

LINKS

Table of n, a(n) for n=1..95.

W. Lang, First 10 rows of the array and more.

W. Lang, Combinatorial Interpretation of Generalized Stirling Numbers, J. Int. Seqs. Vol. 12 (2009) 09.3.3.

FORMULA

a(n,k)= (n!/product(e(n,k,j)!*j!^(e(n,k,j),j=1..n))*product(S1(-1;j,1)^e(n,k,j),j=1..n) = M3(n,k)*product(S1(-1;j,1)^e(n,k,j),j=1..n) with S1(-1;n,1)|= A008279(1,n-1)= [1,1,0,...], n>=1 and the exponent e(n,k,j) of j in the k-th partition of n in the A-St ordering of the partitions of n. M3(n,k)=A036040.

EXAMPLE

[1];[1,1];[0,3,1];[0,0,3,6,1];[0,0,0,0,15,10,1];...

a(4,3)= 3 = 3*S1(-1;2,1)^2. The relevant partition of 4 is (2^2).

CROSSREFS

A000085 (row sums).

A144358 (M31(-2) array).

Sequence in context: A170846 A085604 A306268 * A122848 A272481 A054548

Adjacent sequences:  A144354 A144355 A144356 * A144358 A144359 A144360

KEYWORD

nonn,easy,tabf

AUTHOR

Wolfdieter Lang Oct 09 2008, Oct 28 2008

STATUS

approved

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Last modified April 18 14:39 EDT 2019. Contains 322209 sequences. (Running on oeis4.)