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A198968
11*9^n-1.
1
10, 98, 890, 8018, 72170, 649538, 5845850, 52612658, 473513930, 4261625378, 38354628410, 345191655698, 3106724901290, 27960524111618, 251644717004570, 2264802453041138, 20383222077370250, 183448998696332258, 1651040988266990330
OFFSET
0,1
FORMULA
a(n) = 9*a(n-1)+8. a(n) = 10*a(n-1)-9*a(n-2), n>1.
G.f.: 2*(5 - x)/(1 - 10*x + 9*x^2). - Vincenzo Librandi, Jan 03 2013
MATHEMATICA
CoefficientList[Series[2*(5 - x)/(1 - 10*x + 9*x^2), {x, 0, 30}], x] (* Vincenzo Librandi, Jan 03 2013 *)
LinearRecurrence[{10, -9}, {10, 98}, 30] (* Harvey P. Dale, Jun 26 2013 *)
PROG
(Magma) [11*9^n-1: n in [0..20]]
CROSSREFS
Sequence in context: A044642 A363186 A264462 * A125946 A158513 A125880
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Nov 01 2011
STATUS
approved