|
|
A346005
|
|
Successive numbers arising from the Moessner construction of the cubes on page 64 of Conway-Guy's "Book of Numbers".
|
|
5
|
|
|
0, 1, 3, 3, 8, 12, 6, 27, 27, 9, 64, 48, 12, 125, 75, 15, 216, 108, 18, 343, 147, 21, 512, 192, 24, 729, 243, 27, 1000, 300, 30, 1331, 363, 33, 1728, 432, 36, 2197, 507, 39, 2744, 588, 42, 3375, 675, 45, 4096, 768, 48, 4913, 867, 51, 5832, 972, 54, 6859, 1083, 57, 8000, 1200
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
COMMENTS
|
a(3*k+1) = (k+1)^3 for k >= 0.
|
|
REFERENCES
|
J. H. Conway and R. K. Guy, The Book of Numbers, Copernicus Press, NY, 1996. Sequence can be seen in the successive circled numbers at the top of page 64.
|
|
LINKS
|
|
|
FORMULA
|
a(n) = n if n mod 3 = 0, = ((n+2)/3)^3 if n mod 3 = 1, and otherwise (n+1)^2/3.
|
|
MAPLE
|
f:=proc(n) if (n mod 3) = 0 then n
elif (n mod 3) = 1 then ((n+2)/3)^3;
else (n+1)^2/3; fi; end;
[seq(f(n), n=0..100)];
|
|
PROG
|
(Python)
def A346005(n): return n if n % 3 == 0 else ((n+2)//3)**3 if n % 3 == 1 else (n+1)**2//3 # Chai Wah Wu, Jul 25 2021
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|