|
|
A016130
|
|
Expansion of 1/((1-2x)(1-7x)).
|
|
14
|
|
|
1, 9, 67, 477, 3355, 23517, 164683, 1152909, 8070619, 56494845, 395464939, 2768256621, 19377800443, 135644611293, 949512295435, 6646586100813, 46526102771227, 325682719529661, 2279779036969771
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
a(n) = (7^(n+1) - 2^(n+1))/5. - Lambert Klasen (lambert.klasen(AT)gmx.net), Feb 06 2005
|
|
EXAMPLE
|
1/((1-2x)(1-7x)) = 1 + 9*x + 67*x^2 + 477*x^3 + 3355*x^4 + 23517*x^5 + 164683*x^6 + ...
|
|
MATHEMATICA
|
CoefficientList[Series[1 /((1 - 2 x) (1 - 7 x)), {x, 0, 200}], x] (* Vincenzo Librandi, Jun 24 2013 *)
|
|
PROG
|
(Sage) [lucas_number1(n, 9, 14) for n in range(1, 20)] # Zerinvary Lajos, Apr 23 2009
(Sage) [(7^n - 2^n)/5 for n in range(1, 20)] # Zerinvary Lajos, Jun 04 2009
(Magma) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-2*x) (1-7*x)))); // Vincenzo Librandi, Jun 24 2013
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|