|
|
A008511
|
|
Number of points on surface of 4-dimensional cube.
|
|
2
|
|
|
0, 16, 80, 240, 544, 1040, 1776, 2800, 4160, 5904, 8080, 10736, 13920, 17680, 22064, 27120, 32896, 39440, 46800, 55024, 64160, 74256, 85360, 97520, 110784, 125200, 140816, 157680, 175840
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
a(n) = (n+1)^4 - (n-1)^4 = 8*n + 8*n^3.
G.f.: 16*x*(1+x+x^2)/(1-4*x+6*x^2-4*x^3+x^4). - Colin Barker, Jan 02 2012
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4), a(0)=0, a(1)=16, a(2)=80, a(3)=240. - Harvey P. Dale, Oct 15 2012
|
|
EXAMPLE
|
G.f. = 16*x + 80*x^2 + 240*x^3 + 544*x^4 + 1040*x^5 + 1776*x^6 + 2800*x^7 + ... - Michael Somos, Jun 24 2018
|
|
MAPLE
|
|
|
MATHEMATICA
|
Last[#]-First[#]&/@Partition[Range[-1, 30]^4, 3, 1] (* or *) LinearRecurrence[ {4, -6, 4, -1}, {0, 16, 80, 240}, 30] (* Harvey P. Dale, Oct 15 2012 *)
|
|
PROG
|
(PARI) vector(31, n, 8*(n-1)*(1+(n-1)^2)) \\ G. C. Greubel, Nov 09 2019
(Sage) [8*n*(1+n^2) for n in (0..30)] # G. C. Greubel, Nov 09 2019
(GAP) List([0..30], n-> 8*n*(1+n^2)); # G. C. Greubel, Nov 09 2019
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|