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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A117861 Number of palindromes of length n (in base 9). 1
 8, 8, 72, 72, 648, 648, 5832, 5832, 52488, 52488, 472392, 472392, 4251528, 4251528, 38263752, 38263752, 344373768, 344373768, 3099363912, 3099363912, 27894275208, 27894275208, 251048476872, 251048476872, 2259436291848, 2259436291848, 20334926626632 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 Index entries for linear recurrences with constant coefficients, signature (0,9). FORMULA a(n) = 8*9^floor((n-1)/2). G.f.: 8*x*(1+x)/(1-9*x^2). a(n) = 8*3^(n-2)*(2-(-1)^n). - Bruno Berselli, Oct 24 2011 MATHEMATICA Table[8 9^Floor[(n-1)/2], {n, 50}] (* Harvey P. Dale, Oct 21 2011 *) CROSSREFS Cf. A050683. Cf. A055275. Sequence in context: A019216 A020552 A272961 * A186984 A298962 A082798 Adjacent sequences: A117858 A117859 A117860 * A117862 A117863 A117864 KEYWORD nonn,base,easy AUTHOR Martin Renner, May 02 2006 EXTENSIONS More terms from Harvey P. Dale, Oct 21 2011 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 8 15:25 EDT 2024. Contains 375022 sequences. (Running on oeis4.)