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1, 8, 72, 720, 7920, 95040, 1235520, 17297280, 259459200, 4151347200, 70572902400, 1270312243200, 24135932620800, 482718652416000, 10137091700736000, 223016017416192000, 5129368400572416000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| The asymptotic expansion of the higher order exponential integral E(x,m=1,n=8) ~ exp(-x)/x*(1 - 8/x + 72/x^2 - 720/x^3 + 7920/x^4 - 95040/x^5 + 235520/x^6 - 17297280/x^7 + ...) leads to the sequence given above. See A163931 and A130534 for more information. [Johannes W. Meijer, Oct 20 2009]
a(n) = A173333(n+7,7). [From Reinhard Zumkeller, Feb 19 2010]
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..300
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FORMULA
| a(n) = (n+7)!/7!
E.g.f.: 1/(1-x)^8.
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PROG
| (MAGMA) [Factorial(n+7)/5040: n in [0..25]]; // Vincenzo Librandi, Jul 20 2011
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CROSSREFS
| Cf. A000142, A001710, A001715, A001720, A001725, A001730, A051339. a(n)= A051379(n, 0)*(-1)^n (first unsigned column of triangle).
Sequence in context: A098411 A165323 A082366 * A014479 A013992 A129103
Adjacent sequences: A049385 A049386 A049387 * A049389 A049390 A049391
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KEYWORD
| easy,nonn
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AUTHOR
| Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)
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