OFFSET
1,2
COMMENTS
a(1)=1, for n>1, a(n) is the concatenation of "1", 2(n-1)-1 digits "0" and "1". - Omar E. Pol, Dec 14 2008
LINKS
Index entries for linear recurrences with constant coefficients, signature (101,-100).
FORMULA
Except the first term, a(n)=10^(2n-2)+1. - Robert G. Wilson v, Dec 14 2008
G.f.: x*(1-100*x^2)/(1-x)/(1-100*x). - Robert Israel, Jul 27 2014
EXAMPLE
n ..... a(n)
1 ....... 1
2 ...... 101
3 ..... 10001
4 .... 1000001
5 ... 100000001
MATHEMATICA
LinearRecurrence[{101, -100}, {1, 101, 10001}, 20] (* Paolo Xausa, Oct 05 2024 *)
PROG
(Magma) [1] cat [10^(2*n)+1: n in [1..15]]; // Vincenzo Librandi, Jul 27 2014
CROSSREFS
KEYWORD
easy,nonn,less
AUTHOR
Omar E. Pol, Dec 13 2008
STATUS
approved