A180053 a(1)=1, a(2)=101, a(n) = 1001*a(n-1) for n > 2.

1, 101, 101101, 101202101, 101303303101, 101404606404101, 101506011010505101, 101607517021515606101, 101709124538537121707101, 101810833663075658828808101, 101912644496738734487636909101, 102014557141235473222124546010101

Offset

1,2

Links

Table of n, a(n) for n=1..12.

Index entries for linear recurrences with constant coefficients, signature (1001).

Formula

G.f.: x(1-900*x)/(1-1001*x). - Philippe Deléham, Oct 08 2011

Example

In a column:
                1
              101
           101101
        101202101
     101303303101
  101404606404101

Mathematica

LinearRecurrence[{1001}, {1, 101}, 15] (* Paolo Xausa, Jan 29 2024 *)

Prog

(PARI) a(n)=max(101*1001^(n-2), 1) \\ Charles R Greathouse IV, Oct 08 2011

Crossrefs

Cf. A093645.

Sequence in context: A262633 A261966 A076127 * A138721 A068659 A252491

Adjacent sequences: A180050 A180051 A180052 * A180054 A180055 A180056

Keyword

nonn,easy

Author

Mark Dols, Aug 08 2010

Status

approved