login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A146884 a(n) = 7*Sum_{k=0..n} 6^k. 2
7, 49, 301, 1813, 10885, 65317, 391909, 2351461, 14108773, 84652645, 507915877, 3047495269, 18284971621, 109709829733, 658258978405, 3949553870437, 23697323222629, 142183939335781, 853103636014693, 5118621816088165 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
LINKS
FORMULA
From G. C. Greubel, Oct 12 2022: (Start)
a(n) = (7/5)*(6^(n+1) - 1).
a(n) = 7*A003464(n+1).
a(n) = 7*a(n-1) - 6*a(n-2).
G.f.: 7/((1-x)*(1-6*x)).
E.g.f.: (7/5)*(6*exp(6*x) - exp(x)). (End)
MATHEMATICA
a[n_]:= Sum[7*6^m, {m, 0, n}]; Table[a[n], {n, 0, 30}]
Accumulate[7*6^Range[0, 20]] (* Harvey P. Dale, Dec 18 2021 *)
PROG
(Magma) [n le 2 select 7^n else 7*Self(n-1) -6*Self(n-2): n in [1..31]]; // G. C. Greubel, Oct 12 2022
(SageMath) [(7/5)*(6^(n+1)-1) for n in range(41)] # G. C. Greubel, Oct 12 2022
CROSSREFS
Sequence in context: A189258 A188748 A188986 * A113235 A294261 A294293
KEYWORD
nonn,easy,less,changed
AUTHOR
Roger L. Bagula, Nov 02 2008
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 10:59 EDT 2024. Contains 371277 sequences. (Running on oeis4.)