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A220088
a(n) = 2^n - 81.
1
-80, -79, -77, -73, -65, -49, -17, 47, 175, 431, 943, 1967, 4015, 8111, 16303, 32687, 65455, 130991, 262063, 524207, 1048495, 2097071, 4194223, 8388527, 16777135, 33554351, 67108783, 134217647, 268435375, 536870831, 1073741743, 2147483567, 4294967215
OFFSET
0,1
FORMULA
From Chai Wah Wu, Jan 17 2020: (Start)
a(n) = 3*a(n-1) - 2*a(n-2) for n > 1.
G.f.: (161*x - 80)/((x - 1)*(2*x - 1)). (End)
From Elmo R. Oliveira, Nov 11 2023: (Start)
a(n) = 2*a(n-1) + 81 with a(0) = -80.
E.g.f.: exp(2*x) - 81*exp(x). (End)
MATHEMATICA
Table[2^n - 81, {n, 0, 40}] (* T. D. Noe, Dec 04 2012 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Andreas Rieber, Dec 04 2012
STATUS
approved