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A144275
Lower triangular array called S2hat(-2) related to partition number array A144274.
6
1, 2, 1, 10, 2, 1, 80, 14, 2, 1, 880, 100, 14, 2, 1, 12320, 1140, 108, 14, 2, 1, 209440, 14880, 1180, 108, 14, 2, 1, 4188800, 249280, 15400, 1196, 108, 14, 2, 1, 96342400, 4801280, 255400, 15480, 1196, 108, 14, 2, 1, 2504902400, 108574400, 4888960, 256440, 15512
OFFSET
1,2
COMMENTS
If in the partition array M32khat(-2)= A144274 entries with the same parts number m are summed one obtains this triangle of numbers S2hat(-2). In the same way the Stirling2 triangle A008277 is obtained from the partition array M_3 = A036040.
The first three columns are A008544, A144277, A144278.
LINKS
FORMULA
a(n,m) = Sum_{q=1..p(n,m)} (Product_{j=1..n} |S2(-2;j,1)|^e(n,m,q,j)) if n>=m>=1, else 0. Here p(n,m) = A008284(n,m), the number of m parts partitions of n and e(n,m,q,j) is the exponent of j in the q-th m part partition of n. |S2(-2,n,1)|= A004747(n,1) = A008544(n-1) = (3*n-4)(!^3) (3-factorials) for n>=2 and 1 if n=1.
EXAMPLE
Triangle begins:
[1];
[2,1];
[10,2,1];
[80,14,2,1];
[880,100,14,2,1];
...
CROSSREFS
Row sums A144276.
A144270 (S2hat(-1)).
Sequence in context: A112691 A110169 A144274 * A247236 A011268 A332080
KEYWORD
nonn,easy,tabl
AUTHOR
Wolfdieter Lang, Oct 09 2008
STATUS
approved