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A187556 Triangle read by rows of products of (signless) Stirling numbers of the first kind (A132393) and Stirling numbers of the second kind (A008277). 0
1, 0, 1, 0, 1, 1, 0, 2, 9, 1, 0, 6, 77, 36, 1, 0, 24, 750, 875, 100, 1, 0, 120, 8494, 20250, 5525, 225, 1, 0, 720, 111132, 488824, 257250, 24500, 441, 1, 0, 5040, 1659636, 12685512, 11514069, 2058000, 85652, 784, 1, 0, 40320, 27943920, 357325100, 522796680, 156042999, 12002256, 252252, 1296, 1, 0, 362880, 524580336, 10941291000, 24681106400, 11453045625, 1444332771, 55566000, 652500, 2025, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,8
LINKS
FORMULA
Formula: a(n,k) = s(n,k)*S(n,k), where the s(n,k) are the (signless) Stirling numbers of the first kind and the S(n,k) are the Stirling numbers of the second kind.
EXAMPLE
Triangle begins:
1
0,1
0,1,1
0,2,9,1
0,6,77,36,1
0,24,750,875,100,1
0,120,8494,20250,5525,225,1
0,720,111132,488824,257250,24500,441,1
0,5040,1659636,12685512,11514069,2058000,85652,784,1
MAPLE
seq(seq(abs(combinat[stirling1](n, k))*combinat[stirling2](n, k), k=0..n), n=0..8);
MATHEMATICA
Flatten[Table[Table[Abs[StirlingS1[n, k]]*StirlingS2[n, k], {k, 0, n}], {n, 0, 8}] , 1]
PROG
(Maxima) create_list(abs(stirling1(n, k)*stirling2(n, k)), n, 0, 10, k, 0, n);
CROSSREFS
Sequence in context: A248853 A272003 A128892 * A198103 A105548 A153093
KEYWORD
nonn,easy,tabl
AUTHOR
Emanuele Munarini, Mar 11 2011
STATUS
approved

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Last modified March 28 20:05 EDT 2024. Contains 371254 sequences. (Running on oeis4.)