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!)
 A023545 Convolution of natural numbers >= 2 and natural numbers >= 3. 1
 6, 17, 34, 58, 90, 131, 182, 244, 318, 405, 506, 622, 754, 903, 1070, 1256, 1462, 1689, 1938, 2210, 2506, 2827, 3174, 3548, 3950, 4381, 4842, 5334, 5858, 6415, 7006, 7632, 8294, 8993, 9730, 10506, 11322, 12179, 13078, 14020, 15006, 16037 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 László Németh, Tetrahedron trinomial coefficient transform, arXiv:1905.13475 [math.CO], 2019. Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1). FORMULA a(n) = n*(n^2 + 12*n + 23)/6. - Ralf Stephan, Feb 15 2004; corrected by Lucas Sidiropoulos (lsid77(AT)yahoo.com), Jun 23 2008 a(n) = 4*a(n-1)-6*a(n-2)+4*a(n-3)-a(n-4). G.f.: x*(2-x)*(3-2*x)/(1-x)^4. - Colin Barker, Jun 20 2012 MATHEMATICA CoefficientList[Series[(2-x)*(3-2*x)/(1-x)^4, {x, 0, 40}], x] (* Vincenzo Librandi, Jun 29 2012 *) LinearRecurrence[{4, -6, 4, -1}, {6, 17, 34, 58}, 50] (* Harvey P. Dale, Aug 10 2014 *) PROG (MAGMA) I:=[6, 17, 34, 58]; [n le 4 select I[n] else 4*Self(n-1)-6*Self(n-2)+4*Self(n-3)-Self(n-4): n in [1..50]]; // Vincenzo Librandi, Jun 29 2012 CROSSREFS Sequence in context: A066486 A301719 A056109 * A038633 A083045 A012277 Adjacent sequences:  A023542 A023543 A023544 * A023546 A023547 A023548 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 5 08:34 EST 2021. Contains 349543 sequences. (Running on oeis4.)