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 A194484 Number of ways to arrange 7 indistinguishable points on an n X n X n 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 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 5 X 5 X 5: ......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

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Last modified March 24 15:52 EDT 2018. Contains 301205 sequences. (Running on oeis4.)