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A047851
a(n) = T(3,n), array T given by A047848.
8
1, 2, 8, 44, 260, 1556, 9332, 55988, 335924, 2015540, 12093236, 72559412, 435356468, 2612138804, 15672832820, 94036996916, 564221981492, 3385331888948, 20311991333684, 121871948002100, 731231688012596, 4387390128075572, 26324340768453428, 157946044610720564, 947676267664323380
OFFSET
0,2
COMMENTS
n-th difference of a(n), a(n-1), ..., a(0) is 5^(n-1) for n=1, 2, 3, ...
FORMULA
a(n) = (6^n + 4)/5. - Ralf Stephan, Feb 14 2004
From Philippe Deléham, Oct 05 2009: (Start)
a(0) = 1, a(1) = 2, a(n) = 7*a(n-1) - 6*a(n-2) for n > 1.
G.f.: (1 - 5*x)/(1 - 7*x + 6*x^2). (End)
a(n) = 6*a(n-1) - 4 (with a(0)=1). - Vincenzo Librandi, Aug 06 2010
exp(x)*(exp(5*x) + 4)/5. - Elmo R. Oliveira, Aug 29 2024
MAPLE
a[0]:=0:a[1]:=1:for n from 2 to 50 do a[n]:=6*a[n-1]+1 od: seq(a[n]+1, n=0..20); # Zerinvary Lajos, Mar 20 2008
CROSSREFS
Cf. A047848.
Sequence in context: A362413 A362408 A291697 * A177260 A121747 A261266
KEYWORD
nonn,easy
EXTENSIONS
a(21)-a(24) from Elmo R. Oliveira, Aug 29 2024
STATUS
approved