|
| |
|
|
A046023
|
|
Number of ways to color edges of a tetrahedron using <= n colors.
|
|
1
| |
|
|
0, 1, 12, 87, 416, 1475, 4236, 10437, 22912, 45981, 85900, 151371, 254112, 409487, 637196, 962025, 1414656, 2032537, 2860812, 3953311, 5373600, 7196091, 9507212, 12406637, 16008576, 20443125, 25857676, 32418387, 40311712
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,3
|
|
|
LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 0..10000
Index to sequences with linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
|
|
|
FORMULA
| a(n) = (n^6+3*n^4+8*n^2)/12.
G.f.: x*(1+x)*(1+4*x+20*x^2+4*x^3+x^4)/(1-x)^7. - Colin Barker, Jan 30 2012
|
|
|
MAPLE
| A046023 := n->(n^6+3*n^4+8*n^2)/12;
|
|
|
MATHEMATICA
| LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {0, 1, 12, 87, 416, 1475, 4236}, 30] (* Vincenzo Librandi, Jan 31 2012 *)
|
|
|
PROG
| (PARI) a(n)=(n^6+3*n^4+8*n^2)/12 \\ Charles R Greathouse IV, Jan 31 2012
|
|
|
CROSSREFS
| Cf. A006008.
Sequence in context: A098206 A104911 A091119 * A183721 A180797 A137207
Adjacent sequences: A046020 A046021 A046022 * A046024 A046025 A046026
|
|
|
KEYWORD
| nonn,easy
|
|
|
AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Apr 11 2001
|
| |
|
|
