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A014909
a(1)=1, a(n) = 23*a(n-1) + n.
2
1, 25, 578, 13298, 305859, 7034763, 161799556, 3721389796, 85591965317, 1968615202301, 45278149652934, 1041397442017494, 23952141166402375, 550899246827254639, 12670682677026856712, 291425701571617704392
OFFSET
1,2
FORMULA
a(1)=1, a(2)=25, a(3)=578, a(n) = 25*a(n-1) - 47*a(n-2) + 23*a(n-3). - Harvey P. Dale, Feb 05 2012
G.f.: -(x/((-1+x)^2*(-1+23*x))). - Harvey P. Dale, Feb 05 2012
MATHEMATICA
Transpose[NestList[{First[#]+1, 23Last[#]+First[#]+1}&, {1, 1}, 20]][[2]] (* or *) LinearRecurrence[{25, -47, 23}, {1, 25, 578}, 20] (* Harvey P. Dale, Feb 05 2012 *)
PROG
(Magma) I:=[1, 25, 578]; [n le 3 select I[n] else 25*Self(n-1)-47*Self(n-2)+23*Self(n-3): n in [1..30]]; // Vincenzo Librandi, Feb 05 2012
CROSSREFS
Sequence in context: A264378 A015679 A230454 * A239822 A264220 A228827
KEYWORD
nonn,easy
STATUS
approved