The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A246880 6*((10^n-1)/9)*(10^(n+1))+9*(10^n-1)/9. 2
 0, 609, 66099, 6660999, 666609999, 66666099999, 6666660999999, 666666609999999, 66666666099999999, 6666666660999999999, 666666666609999999999, 66666666666099999999999, 6666666666660999999999999, 666666666666609999999999999, 66666666666666099999999999999 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Numbers of the form 6...609...9 (i.e., consisting of an odd number of digits with the middle digit 0, all digits to the left of the middle digit 6 and all digits to the right of the middle digit 9). LINKS Table of n, a(n) for n=0..14. Index entries for linear recurrences with constant coefficients, signature (111,-1110,1000). FORMULA G.f.: 20/(3-300*x)+1/(x-1)+17/(30*x-3); a(n) = 111*a(n-1)-1110*a(n-2)+1000*a(n-3). - Wesley Ivan Hurt, Sep 15 2014 MAPLE A246880:=n->(6*((10^n - 1)/9))*(10^(n + 1)) + (9*(10^n - 1)/9): seq(A246880(n), n=0..15); # Wesley Ivan Hurt, Sep 15 2014 MATHEMATICA Table[(6*((10^n - 1)/9))*(10^(n + 1)) + (9*(10^n - 1)/9), {n, 15}] (* Wesley Ivan Hurt, Sep 15 2014 *) Join[{0}, CoefficientList[Series[20/(3 x - 300 x^2) + 1/(x^2 - x) + 17/(30 x^2 - 3 x), {x, 0, 30}], x]] (* Wesley Ivan Hurt, Sep 15 2014 *) PROG (PARI) a(n)=6*((10^n-1)/9)*(10^(n+1))+9*(10^n-1)/9 (Magma) [(6*((10^n - 1)/9))*(10^(n + 1)) + (9*(10^n - 1)/9) : n in [0..15]]; // Wesley Ivan Hurt, Sep 15 2014 CROSSREFS Subsequence of A001743, A039434, A111065, A111156, A153806, A169731 and A227793. Sequence in context: A187421 A296825 A186213 * A027514 A246881 A263393 Adjacent sequences: A246877 A246878 A246879 * A246881 A246882 A246883 KEYWORD nonn,base,easy AUTHOR Felix Fröhlich, Sep 06 2014 STATUS approved

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

Last modified August 11 01:05 EDT 2024. Contains 375059 sequences. (Running on oeis4.)