This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A144314 a(n) = 3*n*(6*n+1). 5
 0, 21, 78, 171, 300, 465, 666, 903, 1176, 1485, 1830, 2211, 2628, 3081, 3570, 4095, 4656, 5253, 5886, 6555, 7260, 8001, 8778, 9591, 10440, 11325, 12246, 13203, 14196, 15225, 16290, 17391, 18528, 19701, 20910, 22155, 23436, 24753, 26106, 27495 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Harvey P. Dale, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (3, -3, 1). FORMULA a(n) = A000217(6*n) = A014105(3*n) = A081266(2*n). a(n) = a(n-1)+36*n-15 for n>0, a(0)=0. - Vincenzo Librandi, Dec 27 2010 G.f.: x*(21+15*x)/(1-x)^3. - Vincenzo Librandi, Dec 18 2014 From Wesley Ivan Hurt, Dec 16 2015: (Start) a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>2. a(n) = 3 * A049453(n). (End) MAPLE A144314:=n->3*n*(6*n+1): seq(A144314(n), n=0..70); # Wesley Ivan Hurt, Dec 16 2015 MATHEMATICA Table[3n(6n+1), {n, 0, 40}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 21, 78}, 40] (* Harvey P. Dale, Dec 17 2014 *) CoefficientList[Series[x (21 + 15 x) / (1 - x)^3, {x, 0, 50}], x] (* Vincenzo Librandi, Dec 18 2014 *) PROG (MAGMA) [18*n^2+3*n: n in [0..50]]; // Vincenzo Librandi, Dec 18 2014 (PARI) a(n)=3*n*(6*n+1) \\ Charles R Greathouse IV, Oct 07 2015 CROSSREFS Cf. A000217, A014105, A033585, A049453, A081266, A144312. Sequence in context: A143206 A182754 A045559 * A010009 A172082 A296970 Adjacent sequences:  A144311 A144312 A144313 * A144315 A144316 A144317 KEYWORD nonn,easy AUTHOR Reinhard Zumkeller, Sep 17 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 23 06:15 EST 2019. Contains 319374 sequences. (Running on oeis4.)