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A114958
a(n) = 6*2^(n+1) - 5*(n+1) - 4.
1
3, 10, 29, 72, 163, 350, 729, 1492, 3023, 6090, 12229, 24512, 49083, 98230, 196529, 393132, 786343, 1572770, 3145629, 6291352, 12582803, 25165710, 50331529, 100663172, 201326463, 402653050, 805306229, 1610612592, 3221225323
OFFSET
0,1
FORMULA
From Colin Barker, Apr 30 2019: (Start)
G.f.: (3 - 2*x + 4*x^2) / ((1 - x)^2*(1 - 2*x)).
a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3) for n>2.
(End)
PROG
(Magma) [6*2^(n+1) - 5*(n+1) - 4: n in [0..30] ]; // Vincenzo Librandi, May 18 2011
(PARI) Vec((3 - 2*x + 4*x^2) / ((1 - x)^2*(1 - 2*x)) + O(x^40)) \\ Colin Barker, Apr 30 2019
KEYWORD
easy,nonn
AUTHOR
Creighton Dement, Feb 21 2006
STATUS
approved