[go: up one dir, main page]

login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A007114
Expansion of e.g.f. (1 - x)^x.
(Formerly M0601)
4
1, 0, -2, -3, 4, 30, 66, 0, -496, -1512, 1800, 51480, 487752, 4633200, 50605296, 620703720, 8278947840, 118504008000, 1811156124096, 29452505385600, 507926275873920, 9260774050469760, 178004846331607680, 3597786477984061440, 76284908749415574144, 1693206585883612800000, 39264054809925638534400
OFFSET
0,3
COMMENTS
It appears that a(n) is always positive for n > 9.
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Branko Dragovich, On Summation of p-Adic Series, arXiv:1702.02569 [math.NT], 2017.
FORMULA
a(n) = Sum_{k=0..n} (-1)^k * A008275(k,n-k) n!/k!. - Max Alekseyev, Aug 10 2013
a(n) ~ 2 * n! / n^3 * (1 + (17/2-3*log(n)-3*gamma)/n), where gamma is the Euler-Mascheroni constant (A001620). - Vaclav Kotesovec, Apr 21 2014
MATHEMATICA
CoefficientList[Series[(1-x)^x, {x, 0, 30}], x]*Table[(n-1)!, {n, 1, 31}] (* Vincenzo Librandi, Jun 16 2012 *)
PROG
(PARI) a(n) = sum(k=0, n, (-1)^k*stirling(k, n-k)*n!/k!) \\ Max Alekseyev, Aug 10 2013
(PARI) x='x+O('x^33); Vec(serlaplace(exp(x*log(1 - x)))) \\ Joerg Arndt, Apr 01 2017
(Magma) m:=25; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!((1-x)^x)); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Aug 30 2018
CROSSREFS
Sequence in context: A024633 A326829 A064858 * A191471 A354729 A305205
KEYWORD
sign
AUTHOR
EXTENSIONS
Signs from Christian G. Bower, Nov 15 1998
STATUS
approved