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A199757
a(n) = (7*11^n+1)/2.
1
4, 39, 424, 4659, 51244, 563679, 6200464, 68205099, 750256084, 8252816919, 90780986104, 998590847139, 10984499318524, 120829492503759, 1329124417541344, 14620368592954779, 160824054522502564, 1769064599747528199
OFFSET
0,1
FORMULA
a(n) = 11*a(n-1)-5.
a(n) = 12*a(n-1)-11*a(n-2).
G.f.: (4-9*x)/((1-x)*(1-11*x)).
MATHEMATICA
(7*11^Range[0, 20]+1)/2 (* or *) LinearRecurrence[{12, -11}, {4, 39}, 20] (* Harvey P. Dale, Dec 30 2017 *)
PROG
(Magma) [(7*11^n+1)/2: n in [0..30]];
CROSSREFS
Sequence in context: A224755 A241075 A123618 * A046449 A203211 A214823
KEYWORD
nonn
AUTHOR
Vincenzo Librandi, Nov 10 2011
STATUS
approved