A049396 Expansion of (1-25*x)^(-8/5).

1, 40, 1300, 39000, 1121250, 31395000, 863362500, 23434125000, 629792109375, 16794456250000, 445053090625000, 11733217843750000, 307996968398437500, 8055305327343750000, 210013317462890625000, 5460346254035156250000

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Formula

G.f.: (1-25*x)^(-8/5).

a(n) = (5^n/n!) * product[ k=0..n-1 ] (5*k+8).

a(n) ~ (5/3)*Gamma(3/5)^-1*n^(3/5)*5^(2*n)*{1 + 12/25*n^-1 - ...}. - Joe Keane (jgk(AT)jgk.org), Nov 24 2001

Example

(1-25*x)^(-8/5) = 1+40*x+1300*x^2+39000*x^3+1121250*x^4+31395000*x^5+...

Mathematica

CoefficientList[Series[(1-25x)^-(8/5), {x, 0, 20}], x] (* Harvey P. Dale, May 06 2016 *)

Crossrefs

Cf. A049381.

Sequence in context: A251202 A239189 A188253 * A135644 A165371 A162877

Adjacent sequences: A049393 A049394 A049395 * A049397 A049398 A049399

Keyword

nonn,easy

Author

Joe Keane (jgk(AT)jgk.org)

Extensions

Typo in definition corrected by N. J. A. Sloane, May 06 2016

Status

approved