login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A147589 Concatenation of 2n-1 digits 1 and n-1 digits 0. 1
1, 1110, 1111100, 1111111000, 1111111110000, 1111111111100000, 1111111111111000000, 1111111111111110000000, 1111111111111111100000000, 1111111111111111111000000000, 1111111111111111111110000000000 (list; graph; refs; listen; history; text; internal format)
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 A086887

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 21 04:42 EDT 2021. Contains 343146 sequences. (Running on oeis4.)