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

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A152299 A threes sequence that gets more even factors out: a(n)=(3^n - 1)*(3^n + 1)/2^(4 - Mod[n, 2]). 0
 1, 5, 91, 410, 7381, 33215, 597871, 2690420, 48427561, 217924025, 3922632451, 17651846030, 317733228541, 1429799528435, 25736391511831, 115813761803240, 2084647712458321, 9380914706062445, 168856464709124011 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS FORMULA a(n)=(3^n - 1)*(3^n + 1)/2^(4 - Mod[n, 2]). a(n)=82*a(n-2)-81*a(n-4). G.f.: (1+5x+9x^2)/((1-x)(1-9x)(1+x)(1+9x)). [From R. J. Mathar, Dec 04 2008] MATHEMATICA Clear[a, n]; a[n_] :=(3^n - 1)*(3^n + 1)/2^(4 - Mod[n, 2]); Table[a[n], {n, 0, 30}] CROSSREFS Sequence in context: A158073 A038636 A282052 * A355371 A242945 A243198 Adjacent sequences: A152296 A152297 A152298 * A152300 A152301 A152302 KEYWORD nonn AUTHOR Roger L. Bagula, Dec 02 2008 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 December 8 07:38 EST 2022. Contains 358691 sequences. (Running on oeis4.)