|
| |
|
|
A238777
|
|
a(n) = floor((5^n+1)/(2*3^n)).
|
|
3
|
|
|
|
1, 1, 2, 3, 6, 10, 17, 29, 49, 82, 137, 229, 382, 638, 1063, 1772, 2953, 4923, 8205, 13675, 22792, 37987, 63312, 105521, 175868, 293114, 488524, 814207, 1357012, 2261686, 3769478, 6282463, 10470772, 17451288, 29085480
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,3
|
|
|
COMMENTS
|
a(n) is the rounded-down perimeter of the Vicsek fractal after n iterations. The Vicsek fractal is a subset of the box fractal; for both types, the number of boxes = A000351(n). See illustrations in links.
|
|
|
LINKS
|
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Kival Ngaokrajang, Illustrations of initial terms
Eric Weisstein's World of Mathematics, Box Fractal
Wikipedia, Vicsek Fractal
|
|
|
FORMULA
|
a(n) = A034478(n)/3^n.
|
|
|
MAPLE
|
A238777:=n->floor((5^n+1)/(2*3^n)); seq(A238777(n), n=1..50); # Wesley Ivan Hurt, Mar 09 2014
|
|
|
MATHEMATICA
|
Table[Floor[(5^n + 1)/(2*3^n)], {n, 50}] (* Wesley Ivan Hurt, Mar 09 2014 *)
|
|
|
PROG
|
(Small Basic)
For n = 1 to 40
x = (math.Power(5, n)+1)/(2*math.Power(3, n))
a = math.Floor(x)
TextWindow.Write(a+", ")
Endfor
(PARI)
vector(100, n, floor((5^n+1)/(2*3^n))) \\ Colin Barker, Mar 05 2014
(MAGMA) [Floor((5^n+1)/(2*3^n)): n in [1..40]]; // Vincenzo Librandi, Mar 11 2014
|
|
|
CROSSREFS
|
Cf. A000351, A034478.
Sequence in context: A023614 A001610 A324015 * A344615 A245437 A285665
Adjacent sequences: A238774 A238775 A238776 * A238778 A238779 A238780
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Kival Ngaokrajang, Mar 05 2014
|
|
|
STATUS
|
approved
|
| |
|
|
