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A156198
a(n) = 2*a(n-1)+3 with n>1, a(1)=8.
2
8, 19, 41, 85, 173, 349, 701, 1405, 2813, 5629, 11261, 22525, 45053, 90109, 180221, 360445, 720893, 1441789, 2883581, 5767165, 11534333, 23068669, 46137341, 92274685, 184549373, 369098749, 738197501, 1476395005, 2952790013
OFFSET
1,1
FORMULA
G.f.: (8*x-5*x^2)/(1-3*x+2*x^2). [Philippe Deléham, Feb 09 2009]
a(n) = 3*a(n-1)-2*a(n-2) = 11*2^(n-1)-3. [R. J. Mathar, Feb 19 2009]
MATHEMATICA
LinearRecurrence[{3, -2}, {8, 19}, 30] (* Vincenzo Librandi, May 02 2012 *)
NestList[2#+3&, 8, 30] (* Harvey P. Dale, Oct 17 2016 *)
PROG
(Magma) I:=[8, 19]; [n le 2 select I[n] else 3*Self(n-1)-2*Self(n-2): n in [1..30]]; // _Librandi Vincenzo_, May 02 2012
CROSSREFS
Sequence in context: A089111 A127873 A192975 * A278947 A359265 A153026
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 08 2009
STATUS
approved