|
|
A081042
|
|
7th binomial transform of (1,6,0,0,0,0,0,0,...).
|
|
3
|
|
|
1, 13, 133, 1225, 10633, 88837, 722701, 5764801, 45294865, 351652861, 2703691669, 20620693177, 156208812697, 1176509412085, 8816899947037, 65787638066353, 488998835524129, 3622389432086509, 26752509108528805, 197038045347164329
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
a(n) = 14*a(n-1) - 49*a(n-2) for n>1, a(0)=1, a(1)=13.
a(n) = (6*n+7)*7^(n-1).
a(n) = Sum_{k=0..n} (k+1)*6^k*binomial(n, k).
G.f.: (1-x)/(1-7*x)^2.
|
|
MATHEMATICA
|
CoefficientList[Series[(1 - x)/(1 - 7 x)^2, {x, 0, 30}], x] (* Vincenzo Librandi, Aug 06 2013 *)
LinearRecurrence[{14, -49}, {1, 13}, 20] (* Harvey P. Dale, Jan 24 2014 *)
|
|
PROG
|
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|