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A083335
a(n)=12a(n-2)-25a(n-4).
1
1, 1, 7, 12, 59, 119, 533, 1128, 4921, 10561, 45727, 98532, 425699, 918359, 3965213, 8557008, 36940081, 79725121, 344150647, 742776252, 3206305739, 6920186999, 29871902693, 64472837688, 278305188841, 600669377281, 2592864698767
OFFSET
0,3
COMMENTS
A083334(n)/a(n) converges to sqrt(11)
FORMULA
G.f.: (1+x-5x^2)/(1-12x^2+25x^4)
MATHEMATICA
CoefficientList[Series[(1+x-5x^2)/(1-12x^2+25x^4), {x, 0, 30}], x]
LinearRecurrence[{0, 12, 0, -25}, {1, 1, 7, 12}, 30] (* Harvey P. Dale, Mar 19 2013 *)
CROSSREFS
Sequence in context: A108238 A038278 A266056 * A372734 A358782 A119179
KEYWORD
easy,nonn
AUTHOR
Mario Catalani (mario.catalani(AT)unito.it), Apr 26 2003
STATUS
approved