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A081679
a(n) = (6^n - 5^n - 4^n - 3^n + 4*2^n)/2.
1
1, 1, 1, 16, 199, 1756, 13231, 91876, 608959, 3922396, 24798511, 154802836, 957674719, 5885660236, 35993747791, 219289723396, 1332092132479, 8073205753276, 48838076777071, 295005107805556, 1779844007102239, 10727852491849516, 64609947250462351, 388869415622361316
OFFSET
0,4
COMMENTS
Inverse binomial transform of A081680.
FORMULA
G.f.: (1-19*x+136*x^2-429*x^3+498*x^4)/((1-2*x)*(1-3*x)*(1-4*x)*(1-5*x)*(1-6*x)). - Bruno Berselli, Dec 15 2010
From Elmo R. Oliveira, Sep 12 2024: (Start)
E.g.f.: exp(2*x)*(exp(4*x) - exp(3*x) - exp(2*x) - exp(x) + 4)/2.
a(n) = 20*a(n-1) - 155*a(n-2) + 580*a(n-3) - 1044*a(n-4) + 720*a(n-5) for n > 4. (End)
MATHEMATICA
LinearRecurrence[{20, -155, 580, -1044, 720}, {1, 1, 1, 16, 199}, 40] (* Harvey P. Dale, Jan 20 2022 *)
CROSSREFS
Cf. A081680.
Sequence in context: A016226 A332854 A154240 * A154249 A226869 A257289
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Mar 30 2003
STATUS
approved