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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A132763 a(n) = n*(n+21). 12
 0, 22, 46, 72, 100, 130, 162, 196, 232, 270, 310, 352, 396, 442, 490, 540, 592, 646, 702, 760, 820, 882, 946, 1012, 1080, 1150, 1222, 1296, 1372, 1450, 1530, 1612, 1696, 1782, 1870, 1960, 2052, 2146, 2242, 2340, 2440, 2542, 2646, 2752, 2860, 2970, 3082, 3196, 3312 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS G. C. Greubel, Table of n, a(n) for n = 0..5000 Felix P. Muga II, Extending the Golden Ratio and the Binet-de Moivre Formula, Preprint on ResearchGate, March 2014. Index entries for linear recurrences with constant coefficients, signature (3,-3,1). FORMULA a(n) = n*(n + 21). a(n) = 2*n + a(n-1) + 20 (with a(0)=0). - Vincenzo Librandi, Aug 03 2010 a(0)=0, a(1)=22, a(2)=46, a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3). - Harvey P. Dale, May 25 2014 From Amiram Eldar, Jan 16 2021: (Start) Sum_{n>=1} 1/a(n) = H(21)/21 = A001008(21)/A102928(21) = 18858053/108636528, where H(k) is the k-th harmonic number. Sum_{n>=1} (-1)^(n+1)/a(n) = 2*log(2)/21 - 166770367/4888643760. (End) From Stefano Spezia, Jan 30 2021: (Start) O.g.f.: 2*x*(11 - 10*x)/(1 - x)^3. E.g.f.: x*(22 + x)*exp(x). (End) MATHEMATICA Table[n(n+21), {n, 0, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 22, 46}, 50] (* Harvey P. Dale, May 25 2014 *) PROG (PARI) a(n)=n*(n+21) \\ Charles R Greathouse IV, Oct 07 2015 (Sage) [n*(n+21) for n in (0..50)] # G. C. Greubel, Mar 14 2022 CROSSREFS Cf. A001008, A002378, A005563, A028347, A028552, A028557, A028560, A028563, A028566, A028569, A098603, A098847, A098848, A098849, A098850, A102928, A120071, A132759, A132760, A132761, A132762, A132764, A132765, A132766, A132767. Sequence in context: A335297 A158862 A161666 * A250723 A044099 A044480 Adjacent sequences:  A132760 A132761 A132762 * A132764 A132765 A132766 KEYWORD easy,nonn AUTHOR Omar E. Pol, Aug 28 2007 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 July 1 03:30 EDT 2022. Contains 354947 sequences. (Running on oeis4.)