The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons 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 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A021824 Expansion of 1/((1-x)(1-4x)(1-6x)(1-9x)). 1
 1, 20, 267, 3010, 31073, 304920, 2901319, 27075950, 249555405, 2281579300, 20749095731, 188036746170, 1700122392697, 15347941075760, 138412864844703, 1247405586235270, 11236794818538149, 101192043527859900 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..200 FORMULA a(n) = (9^(n+3) - 4*6^(n+3) + 4^(n+4) - 1)/120. [Yahia Kahloune, Jul 05 2013] MATHEMATICA CoefficientList[Series[1 / ((1 - x) (1 - 4 x) (1 - 6 x) (1 - 9 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 11 2013 *) CROSSREFS Sequence in context: A021854 A025939 A278773 * A125455 A019928 A025934 Adjacent sequences:  A021821 A021822 A021823 * A021825 A021826 A021827 KEYWORD nonn,easy AUTHOR 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.

Last modified December 7 21:29 EST 2021. Contains 349589 sequences. (Running on oeis4.)