OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,0,0,0,11,0,0,0,0,0,0,0,0,-10).
FORMULA
a(n) = 2*A010785(n).
G.f.: 2*x*(9*x^8+8*x^7+7*x^6+6*x^5+5*x^4+4*x^3+3*x^2+2*x+1) / ((x-1)*(x^2+x+1)*(x^6+x^3+1)*(10*x^9-1)). - Colin Barker, Sep 18 2013
a(n) = 11*a(n-9) - 10*a(n-18). - Wesley Ivan Hurt, Jan 03 2024
MATHEMATICA
Join[{0}, 2*Flatten[Table[FromDigits[PadRight[{}, n, d]], {n, 5}, {d, 9}]]] (* or *) LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 0, 0, 0, 0, 0, 0, 0, -10}, {0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 22, 44, 66, 88, 110, 132, 154, 176}, 50] (* Harvey P. Dale, Jun 20 2014 *)
CoefficientList[Series[2 x (9 x^8 + 8 x^7 + 7 x^6 + 6 x^5 + 5 x^4 + 4 x^3 + 3 x^2 + 2 x + 1)/((x - 1) (x^2 + x + 1) (x^6 + x^3 + 1) (10 x^9 - 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 21 2014 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Omar E. Pol, Dec 16 2008
STATUS
approved