OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (7,1,-7).
FORMULA
From Chai Wah Wu, Mar 11 2021: (Start)
a(n) = 7*a(n-1) + a(n-2) - 7*a(n-3) for n > 2.
G.f.: -(1 + 2*x - 7*x^2)/((1 - x)*(1 + x)*(1 - 7*x)). (End)
From G. C. Greubel, Feb 03 2024: (Start)
E.g.f.: (1/6)*(-3*exp(-x) + 2*exp(x) + 7*exp(7*x)). (End)
MATHEMATICA
Table[(7^(n+1) -3*(-1)^n +2)/6, {n, 0, 50}]
PROG
(Magma) [(7^(n+1)-3*(-1)^n+2)/6: n in [0..50]]; // G. C. Greubel, Feb 03 2024
(SageMath) [(7^(n+1)-3*(-1)^n+2)/6 for n in range(51)] # G. C. Greubel, Feb 03 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Mar 15 2005
EXTENSIONS
Edited by N. J. A. Sloane, May 29 2007
STATUS
approved