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A120662
Expansion of x*(12 +101*x -189*x^2)/((1+2*x)*(1-3*x)*(1-5*x)).
1
0, 12, 173, 861, 4979, 25545, 132419, 670689, 3390203, 17039337, 85505555, 428366577, 2144524907, 10730349369, 53675623811, 268448345025, 1342455212891, 6712910908041, 33566470310387, 167838076383633
OFFSET
0,2
FORMULA
From Colin Barker, Nov 01 2012: (Start)
a(n) = 6*a(n-1) + a(n-2) - 30*a(n-3) for n>3.
G.f.: x*(12 +101*x -189*x^2)/((1+2*x)*(1-3*x)*(1-5*x)). (End)
MATHEMATICA
LinearRecurrence[{6, 1, -30}, {0, 12, 173, 861}, 20] (* Harvey P. Dale, Jan 09 2019 *)
PROG
(Magma) I:=[12, 173, 861]; [0] cat [n le 3 select I[n] else 6*Self(n-1) + Self(n-2) -30*Self(n-3): n in [1..31]]; // G. C. Greubel, Dec 25 2022
(SageMath)
@CachedFunction
def a(n): # a = A120662
if (n<4): return (0, 12, 173, 861)[n]
else: return 6*a(n-1) + a(n-2) -30*a(n-3)
[a(n) for n in range(41)] # G. C. Greubel, Dec 25 2022
CROSSREFS
Sequence in context: A187361 A366235 A239335 * A230815 A099930 A307549
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Aug 10 2006
EXTENSIONS
Edited by N. J. A. Sloane, Jul 13 2007
Meaningful name using g.f. from Joerg Arndt, Dec 26 2022
STATUS
approved