login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A194484 Number of ways to arrange 7 indistinguishable points on an nXnXn triangular grid so that no four points are in the same row or diagonal 0
0, 0, 0, 63, 4080, 83745, 927471, 6924357, 39196161, 180512640, 708150465, 2442836682, 7582054194, 21540941994, 56763356130, 140189208510, 327211061058, 726712057836, 1544399756262, 3155463833625, 6223010262480, 11886291766899 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Column 7 of A194485

LINKS

Table of n, a(n) for n=1..22.

FORMULA

Empirical: a(n) = (1/645120)*n^14 + (1/92160)*n^13 - (1/30720)*n^12 - (79/92160)*n^11 + (101/30720)*n^10 + (757/129024)*n^9 - (3049/92160)*n^8 - (34099/645120)*n^7 + (6613/15360)*n^6 - (16859/23040)*n^5 + (1043/3840)*n^4 + (2759/5040)*n^3 - (753/1120)*n^2 + (13/56)*n

EXAMPLE

Some solutions for 5X5X5

......1..........0..........0..........1..........0..........0..........0

.....0.1........1.0........1.1........0.1........1.1........0.1........0.0

....1.1.1......0.1.0......1.1.1......1.0.0......0.0.0......0.1.1......1.0.1

...0.0.0.0....1.1.0.0....1.0.1.0....1.0.1.0....1.1.0.1....0.1.1.0....1.1.0.1

..1.1.0.0.0..0.1.0.1.1..0.0.0.0.0..0.1.0.0.1..0.1.0.1.0..1.0.0.0.1..1.0.0.1.0

CROSSREFS

Sequence in context: A180926 A267963 A268028 * A195620 A238994 A069407

Adjacent sequences:  A194481 A194482 A194483 * A194485 A194486 A194487

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 26 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 8 12:55 EST 2016. Contains 278945 sequences.