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A186942
a(n)=2(4^n-n*2^n)-1.
1
1, 3, 15, 79, 383, 1727, 7423, 30975, 126975, 515071, 2076671, 8343551, 33456127, 134004735, 536412159, 2146500607, 8587837439, 34355281919, 137429516287, 549735890943, 2198981312511, 8796004941823, 35184187539455, 140737102479359, 562949148114943, 2251798135963647
OFFSET
0,2
COMMENTS
A factor in the Hankel transform A186941.
FORMULA
G.f.: (1-6x+16x^2-8x^3)/((1-2x)^2*(1-5x+4x^2)).
MATHEMATICA
Table[2(4^n-n 2^n)-1, {n, 0, 30}] (* or *) LinearRecurrence[{9, -28, 36, -16}, {1, 3, 15, 79}, 30] (* Harvey P. Dale, Feb 22 2023 *)
CROSSREFS
Sequence in context: A299568 A031884 A337284 * A193913 A292097 A052755
KEYWORD
nonn,easy
AUTHOR
Paul Barry, Mar 01 2011
STATUS
approved