A049393 - OEIS

%I #13 Apr 28 2018 12:49:28

%S 1,-5,-50,-750,-13125,-249375,-4987500,-103312500,-2195390625,

%T -47566796875,-1046469531250,-23307730468750,-524423935546875,

%U -11900389306640625,-272008898437500000,-6256204664062500000,-144674732856445312500,-3361559969311523437500

%N Expansion of (1-25*x)^(1/5).

%H Seiichi Manyama, <a href="/A049393/b049393.txt">Table of n, a(n) for n = 0..500</a>

%F G.f.: (1-25*x)^(1/5).

%F a(n) = 5^n/n! * product[ k=0..n-1 ] (5*k-1).

%F a(n) ~ -1/5*Gamma(4/5)^-1*n^(-6/5)*5^(2*n)*{1 + 3/25*n^-1 + ...}. - Joe Keane (jgk(AT)jgk.org), Nov 24 2001

%p A049393 := proc(n)

%p     coeftayl((1-25*x)^(1/5), x=0, n);

%p end proc:

%p seq(A049393(n), n=0..20); # _Wesley Ivan Hurt_, Jul 13 2014

%t CoefficientList[Series[(1 - 25 x)^(1/5), {x, 0, 20}], x] (* _Wesley Ivan Hurt_, Jul 13 2014 *)

%o (PARI) Vec(taylor((1-25*x)^(1/5), x, 40)) \\ _Michel Marcus_, Jul 16 2014

%Y Cf. A049382.

%K sign,easy

%O 0,2

%A Joe Keane (jgk(AT)jgk.org)