OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..400
Index entries for linear recurrences with constant coefficients, signature (81, -2916, 61236, -826686, 7440174, -44641044, 172186884, -387420489, 387420489).
FORMULA
G.f.: (-1 + 1/(1-9*x)^9)/(81*x).
a(n) = 9^(n-1)*binomial(n+9, 8).
a(0)=1, a(1)=45, a(2)=1485, a(3)=40095, a(4)=938223, a(5)=19702683, a(6)=379980315, a(7)=6839645670, a(8)=116273976390, a(n)=81*a(n-1)- 2916*a(n-2)+ 61236*a(n-3)- 826686*a(n-4)+ 7440174*a(n-5)- 44641044*a(n-6)+ 172186884*a(n-7)- 387420489*a(n-8)+ 387420489*a(n-9). - Harvey P. Dale, Apr 27 2013
MATHEMATICA
CoefficientList[Series[(-1+1/(1-9*x)^9)/(81*x), {x, 0, 30}], x] (* or *) LinearRecurrence[{81, -2916, 61236, -826686, 7440174, -44641044, 172186884, -387420489, 387420489}, {1, 45, 1485, 40095, 938223, 19702683, 379980315, 6839645670, 116273976390}, 20] (* Harvey P. Dale, Apr 27 2013 *)
Table[9^(n - 1)*Binomial[n + 9, 8], {n, 0, 30}] (* G. C. Greubel, Aug 16 2018 *)
PROG
(PARI) vector(30, n, n--; 9^(n-1)*binomial(n+9, 8)) \\ G. C. Greubel, Aug 16 2018
(Magma) [9^(n-1)*Binomial(n+9, 8): n in [0..30]]; // G. C. Greubel, Aug 16 2018
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
STATUS
approved