OFFSET
1,2
REFERENCES
John H. Conway and Richard K. Guy, 'The Book of Numbers', Copernicus Pub. Co., 1996
Peter Pearce and Susan Pearce, 'Polyhedra primer', Van Nostrand Reinhold, 1978
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
G.f.: x*(1 + 89*x + 251*x^2 + 43*x^3)/(1-x)^4. - R. J. Mathar, Nov 10 2011
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4). - Vincenzo Librandi, Jul 01 2012
E.g.f.: 43 + (-43 + 44*x + 24*x^2 + 64*x^3)*exp(x). - G. C. Greubel, Nov 14 2019
MAPLE
seq(((8*n-7)^3 +(8*n-1))/8, n=1..40); # G. C. Greubel, Nov 14 2019
MATHEMATICA
CoefficientList[Series[(1+89*x+251*x^2+43*x^3)/(x-1)^4, {x, 0, 40}], x] (* Vincenzo Librandi, Jul 01 2012 *)
LinearRecurrence[{4, -6, 4, -1}, {1, 93, 617, 1957}, 30] (* Harvey P. Dale, Mar 16 2013 *)
Table[((8*n-7)^3 +(8*n-1))/8, {n, 40}] (* G. C. Greubel, Nov 14 2019 *)
PROG
(Magma) I:=[1, 93, 617, 1957]; [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..40]]; // Vincenzo Librandi, Jul 01 2012
(PARI) a(n)=64*n^3-168*n^2+148*n-43 \\ Charles R Greathouse IV, Apr 25 2016
(Sage) [((8*n-7)^3 +(8*n-1))/8 for n in (1..40)] # G. C. Greubel, Nov 14 2019
(GAP) List([1..40], n-> ((8*n-7)^3 +(8*n-1))/8); # G. C. Greubel, Nov 14 2019
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Chris G. Spies-Rusk (chaosorder4(AT)gmail.com), May 05 2009, May 11 2009, May 19 2009
EXTENSIONS
Edited by G. C. Greubel, Nov 14 2019
STATUS
approved