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

Author

Omar E. Pol, Nov 08 2008

Keywords

• easy
• nonn
• base

Comments

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

Examples

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

Links

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

Crossrefs

Cf. A138118, A147537, A147590.

Programs

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

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

Extensions

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