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A048163
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Sum_{k=1..n} ((k-1)!)^2*Stirling2(n,k)^2.
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2
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1, 2, 14, 230, 6902, 329462, 22934774, 2193664790, 276054834902, 44222780245622, 8787513806478134, 2121181056663291350, 611373265185174628502, 207391326125004608457782, 81791647413265571604175094, 37109390748309009878392597910
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| K. Vesztergombi, Permutations with restriction of middle strength, Stud. Sci. Math. Hungar., 9 (1974), 181-185.
Lovasz, L. and Vesztergombi, K.; Restricted permutations and Stirling numbers. Combinatorics (Proc. Fifth Hungarian Colloq., Keszthely, 1976), Vol. II, pp. 731-738, Colloq. Math. Soc. Janos Bolyai, 18, North-Holland, Amsterdam-New York, 1978.
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FORMULA
| (-1)^(n-1) * Sum[k=0..n-1, (-1)^k*(k+1)^(n-1)*k!*Stirling2(k, n) ]. - Ralf Stephan, Oct 27 2004
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CROSSREFS
| Main diagonal of array A099594.
Sequence in context: A153668 A105749 A118086 * A093548 A052215 A053846
Adjacent sequences: A048160 A048161 A048162 * A048164 A048165 A048166
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), R. K. Guy
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