|
|
A274074
|
|
a(n) = 6^n+(-1)^n.
|
|
0
|
|
|
2, 5, 37, 215, 1297, 7775, 46657, 279935, 1679617, 10077695, 60466177, 362797055, 2176782337, 13060694015, 78364164097, 470184984575, 2821109907457, 16926659444735, 101559956668417, 609359740010495, 3656158440062977, 21936950640377855, 131621703842267137
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
LINKS
|
|
|
FORMULA
|
O.g.f.: (2-5*x) / ((1+x)*(1-6*x)).
E.g.f.: exp(-x) + exp(6*x).
a(n) = 5*a(n-1)+6*a(n-2) for n>1.
|
|
MATHEMATICA
|
Array[6^# + (-1)^# &, 23, 0] (* or *)
LinearRecurrence[{5, 6}, {2, 5}, 23] (* or *)
CoefficientList[ Series[(5x -2)/(6x^2 + 5x -1), {x, 0, 23}], x] (* Robert G. Wilson v, Jan 01 2017 *)
|
|
PROG
|
(PARI) Vec((2-5*x)/((1+x)*(1-6*x)) + O(x^30))
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|