OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (6, -15, 20, -15, 6, -1).
FORMULA
a(n) = 5*n^5 + 3*n^3 + 2*n^2.
G.f.: 2x*(5+66x+156x^2+70x^3+3x^4)/(1-x)^6. - R. J. Mathar, Nov 14 2007
a(0)=0, a(1)=10, a(2)=192, a(3)=1314, a(4)=5344, a(5)=16050, a(n)= 6*a(n-1)- 15*a(n-2)+20*a(n-3)-15*a(n-4)+6*a(n-5)-a(n-6). - Harvey P. Dale, Apr 25 2012
EXAMPLE
a(4)=5344 because 4^5=1024, 5*1024=5120, 4^3=64, 3*64=192, 4^2=16, 2*16=32 and we can write 5120+192+32=5344.
MAPLE
MATHEMATICA
Table[5n^5+3n^3+2n^2, {n, 0, 40}] (* or *) LinearRecurrence[ {6, -15, 20, -15, 6, -1}, {0, 10, 192, 1314, 5344, 16050}, 40] (* Harvey P. Dale, Apr 25 2012 *)
CoefficientList[Series[2 x (5 + 66 x + 156 x^2 + 70 x^3 + 3x^4)/(1 - x)^6, {x, 0, 50}], x] (* Vincenzo Librandi, May 21 2014 *)
PROG
(Magma)[5*n^5+3*n^3+2*n^2: n in [0..50]]; // Vincenzo Librandi, Dec 14 2010
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Nov 04 2007
EXTENSIONS
More terms from Vincenzo Librandi, Dec 14 2010
STATUS
approved