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A036551 a(n) = 2^(n-1)*(3^n-1) + 1. 2
1, 3, 17, 105, 641, 3873, 23297, 139905, 839681, 5038593, 30232577, 181397505, 1088389121, 6530342913, 39182073857, 235092475905, 1410554920961, 8463329656833, 50779978203137, 304679869743105, 1828079219507201, 10968475319140353, 65810851919036417 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(n) = T(n, n), array T given by A048471.
From Colin Barker, Aug 24 2016: (Start)
a(n) = 9*a(n-1)-20*a(n-2)+12*a(n-3) for n>2.
G.f.: (1-6*x+10*x^2) / ((1-x)*(1-2*x)*(1-6*x)).
(End)
PROG
(PARI) Vec((1-6*x+10*x^2)/((1-x)*(1-2*x)*(1-6*x)) + O(x^30)) \\ Colin Barker, Aug 24 2016
CROSSREFS
Cf. A048471.
Sequence in context: A020069 A020024 A264963 * A162479 A194780 A074563
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Simpler definition from Ralf Stephan, Feb 17 2004
Corrected by T. D. Noe, Nov 07 2006
STATUS
approved

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Last modified March 28 04:13 EDT 2024. Contains 371235 sequences. (Running on oeis4.)