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A343539
a(n) = (2*n+1)*Lucas(2*n+1).
1
1, 12, 55, 203, 684, 2189, 6773, 20460, 60707, 177631, 513996, 1473817, 4194025, 11858508, 33345679, 93320819, 260079468, 722163365, 1998685277, 5515470636, 15180186491, 41680890247, 114197428620, 312260427313, 852296004049, 2322415005324, 6318599122663, 17166545274395
OFFSET
0,2
FORMULA
G.f.: (1-x)*(1 + 7*x + x^2)/(1 - 3*x + x^2)^2.
a(n) = (2*n+1)*A000032(2*n+1).
a(n) = A146005(2*n+1).
a(n) = 6*a(n-1) - 11*a(n-2) + 6*a(n-3) - a(n-4). - Wesley Ivan Hurt, Apr 19 2021
MATHEMATICA
Table[(2n+1) LucasL[2n+1], {n, 0, 30}] (* Wesley Ivan Hurt, Apr 19 2021 *)
PROG
(Magma) [(2*n+1)*Lucas(2*n+1) : n in [0..40]]; // Wesley Ivan Hurt, Apr 19 2021
(PARI) a(n) = (2*n+1)*(fibonacci(2*n+2)+fibonacci(2*n)) \\ Andrew Howroyd, Jan 01 2024
CROSSREFS
Bisection of A146005.
Sequence in context: A275249 A143856 A207102 * A229424 A009653 A133001
KEYWORD
nonn,easy
AUTHOR
Harry Richman, Apr 16 2021
STATUS
approved