This site is supported by donations to The OEIS Foundation.

The October issue of the Notices of the Amer. Math. Soc. has an article about the OEIS.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A063490 a(n) = (2*n - 1)*(7*n^2 - 7*n + 6)/6. 19
 1, 10, 40, 105, 219, 396, 650, 995, 1445, 2014, 2716, 3565, 4575, 5760, 7134, 8711, 10505, 12530, 14800, 17329, 20131, 23220, 26610, 30315, 34349, 38726, 43460, 48565, 54055, 59944, 66246, 72975, 80145, 87770, 95864, 104441, 113515 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) = Sum of A064788(k) for k = n^2-2*n+2,...,n^2. - Lior Manor, Jan 13 2013 LINKS Harry J. Smith, Table of n, a(n) for n = 1..1000 T. P. Martin, Shells of atoms, Phys. Rep., 273 (1996), 199-241, eq. (10). Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1). FORMULA G.f.: x*(1+x)*(1+5*x+x^2)/(1-x)^4. - Colin Barker, Mar 02 2012 From G. C. Greubel, Dec 01 2017: (Start) a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). E.g.f.: (-6 + 12*x + 21*x^2 + 14*x^3)*exp(x)/6 + 1. (End) MATHEMATICA Table[(2*n-1)*(7*n^2-7*n+6)/6, {n, 1, 50}] (* or *) LinearRecurrenc[{4, -6, 4, -1}, {1, 10, 40, 105}, 50] (* G. C. Greubel, Dec 01 2017 *) PROG (PARI) { for (n=1, 1000, write("b063490.txt", n, " ", (2*n - 1)*(7*n^2 - 7*n + 6)/6) ) } \\ Harry J. Smith, Aug 23 2009 (PARI) x='x+O('x^30); Vec(serlaplace((-6 + 12*x + 21*x^2 + 14*x^3 )*exp(x)/6 + 1)) \\ G. C. Greubel, Dec 01 2017 (MAGMA) [(2*n-1)*(7*n^2-7*n+6)/6: n in [1..30]]; // G. C. Greubel, Dec 01 2017 CROSSREFS 1/12*t*(2*n^3-3*n^2+n)+2*n-1 for t = 2, 4, 6, ... gives A049480, A005894, A063488, A001845, A063489, A005898, A063490, A057813, A063491, A005902, A063492, A005917, A063493, A063494, A063495, A063496. Cf. A064788. Sequence in context: A033583 A131037 A071233 * A251121 A002419 A199826 Adjacent sequences:  A063487 A063488 A063489 * A063491 A063492 A063493 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Aug 01 2001 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 25 15:05 EDT 2018. Contains 315391 sequences. (Running on oeis4.)