|
|
A097705
|
|
a(n) = 4*a(n-1) + 17*a(n-2), a(1)=1, a(2)=4.
|
|
2
|
|
|
1, 4, 33, 200, 1361, 8844, 58513, 384400, 2532321, 16664084, 109705793, 722112600, 4753448881, 31289709724, 205967469873, 1355794944800, 8924626767041, 58747021129764, 386706739558753, 2545526317441000
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
This is one of only two Lucas-type sequences whose 8th term is a square.
|
|
LINKS
|
|
|
FORMULA
|
G.f.: 1/(1-4x-17x^2).
|
|
MAPLE
|
f:= gfun:-rectoproc({a(n) = 4*a(n-1) + 17*a(n-2), a(1)=1, a(2)=4}, a(n), remember): map(f, [$0..20]); # Georg Fischer, Jun 18 2021
|
|
PROG
|
(Maxima)
a[0]:0$
a[1]:1$
a[n]:=4*a[n-1] + 17*a[n-2]$
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|