OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..100
Index entries for linear recurrences with constant coefficients, signature (10,0,1,-10).
FORMULA
G.f.: (x*(2+x^2)) / ((x-1)*(10*x-1)*(1+x+x^2)). - R. J. Mathar, Nov 21 2011
MATHEMATICA
LinearRecurrence[{10, 0, 1, -10}, {2, 20, 201, 2012}, 40] (* Vincenzo Librandi, Nov 23 2011 *)
Table[FromDigits[PadRight[{}, n, {2, 0, 1}]], {n, 20}] (* Harvey P. Dale, Sep 18 2018 *)
PROG
(Magma) I:=[2, 20, 201, 2012]; [n le 4 select I[n] else 10*Self(n-1)+Self(n-3)-10*Self(n-4): n in [1..20]]; // Vincenzo Librandi, Nov 23 2011
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
STATUS
approved