A134230 a(n) = (10^n+1)^2-1.

3, 120, 10200, 1002000, 100020000, 10000200000, 1000002000000, 100000020000000, 10000000200000000, 1000000002000000000, 100000000020000000000, 10000000000200000000000, 1000000000002000000000000, 100000000000020000000000000, 10000000000000200000000000000

Offset

0,1

Comments

Previous name was: -1 + Sum of first 10^n + 1 odd numbers.

Links

Colin Barker, Table of n, a(n) for n = 0..499

Index entries for linear recurrences with constant coefficients, signature (110,-1000).

Formula

a(n) = (10^n+1)^2-1. - N. J. A. Sloane, Oct 15 2007

a(n) = 110*a(n-1)-1000*a(n-2). - Colin Barker, Jan 27 2015

G.f.: -3*(70*x-1) / ((10*x-1)*(100*x-1)). - Colin Barker, Jan 27 2015

Prog

(PARI) Vec(-3*(70*x-1)/((10*x-1)*(100*x-1))  + O(x^100)) \\ Colin Barker, Jan 27 2015

Crossrefs

Cf. A134228, A134229.

Sequence in context: A214312 A343831 A185554 * A321109 A307936 A308142

Adjacent sequences: A134227 A134228 A134229 * A134231 A134232 A134233

Keyword

easy,nonn

Author

Enoch Haga, Oct 14 2007

Extensions

Edited by N. J. A. Sloane, Oct 15 2007

Offset and name corrected by Arkadiusz Wesolowski, Jun 12 2013

New name (using formula by N. J. A. Sloane) from Joerg Arndt, Jan 27 2015

Status

approved