A147589 Concatenation of 2n-1 digits 1 and n-1 digits 0.

1, 1110, 1111100, 1111111000, 1111111110000, 1111111111100000, 1111111111111000000, 1111111111111110000000, 1111111111111111100000000, 1111111111111111111000000000, 1111111111111111111110000000000

Offset

1,2

Comments

a(n) is also A147590(n) written in base 2.

Links

Table of n, a(n) for n=1..11.

Index entries for linear recurrences with constant coefficients, signature (1010,-10000).

Formula

a(n) = A138118(n)/10.

a(n) = {[10^(2*n-1)-1]*10^(n-1)}/9, with n>=1. - Paolo P. Lava, Nov 26 2008

G.f.: x*(100*x+1) / ((10*x-1)*(1000*x-1)). - Colin Barker, Jul 08 2014

Example

n .......... a(n)
1 ........... 1
2 ......... 1110
3 ....... 1111100
4 ..... 1111111000
5 ... 1111111110000

Prog

(PARI) vector(100, n, 10^(-2+n)*(-10+100^n)/9) \\ Colin Barker, Jul 08 2014
(PARI) Vec(x*(100*x+1)/((10*x-1)*(1000*x-1)) + O(x^100)) \\ Colin Barker, Jul 08 2014

Crossrefs

Cf. A138118, A147537, A147590.

Sequence in context: A252010 A036105 A036103 * A287283 A277927 A367814

Adjacent sequences: A147586 A147587 A147588 * A147590 A147591 A147592

Keyword

easy,nonn,base

Author

Omar E. Pol, Nov 08 2008

Extensions

Keyword:base added by Charles R Greathouse IV, Apr 28 2010

Status

approved