OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..100
Index entries for linear recurrences with constant coefficients, signature (101,-100).
FORMULA
From Colin Barker, May 31 2015: (Start)
a(n) = (2^(3+2*n)*5^(1+2*n)-7)/33.
a(n) = 100*a(n-1) + 21.
a(n) = 101*a(n-1) - 100*a(n-2).
G.f.: (20*x+1) / ((x-1)*(100*x-1)).
(End)
EXAMPLE
a(7) = 1 21 21 21 21 21 21 21.
MATHEMATICA
Table[FromDigits[PadRight[{1}, n, {1, 2}]], {n, 1, 31, 2}] (* or *) LinearRecurrence[{101, -100}, {1, 121}, 30] (* Harvey P. Dale, Aug 17 2013 *)
PROG
(PARI) Vec((20*x+1)/((x-1)*(100*x-1)) + O(x^30)) \\ Colin Barker, May 31 2015
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Ctibor O. Zizka, Apr 19 2008
EXTENSIONS
More terms from Harvey P. Dale, Aug 17 2013
STATUS
approved