|
Search: id:A133648
|
|
|
| A133648 |
|
a(n) = 2*3^n + 3^(n-1) - (n+1). |
|
+0
2
|
|
| 5, 18, 59, 184, 561, 1694, 5095, 15300, 45917, 137770, 413331, 1240016, 3720073, 11160246, 33480767, 100442332, 301327029, 903981122, 2711943403, 8135830248, 24407490785, 73222472398, 219667417239, 659002251764, 1977006755341
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Inverse binomial transform of A133648 = A133649.
|
|
FORMULA
|
O.g.f.: -x*(5-7*x+4*x^2)/[(-1+x)^2*(-1+3*x)] . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 07 2008
|
|
EXAMPLE
|
a(3) = 2*3^3 + 3^2 - 4 = 2*27 + 9 - 4.
|
|
MATHEMATICA
|
Table[2*3^n + 3^(n - 1) - (n + 1), {n, 1, 50}] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Sep 20 2007
|
|
CROSSREFS
|
Cf. A000244, A133649.
Sequence in context: A128553 A000340 A034567 this_sequence A099449 A104630 A062809
Adjacent sequences: A133645 A133646 A133647 this_sequence A133649 A133650 A133651
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Gary W. Adamson (qntmpkt(AT)yahoo.com), Sep 19 2007
|
|
EXTENSIONS
|
More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Sep 20 2007
|
|
|
Search completed in 0.002 seconds
|
