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URL: https://oeis.org/A178351

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A178351
Number of collinear point 5-tuples in a 7 X 7 X 7 X ... n-dimensional cubic grid.
1
0, 21, 364, 4833, 58360, 676941, 7731364, 88086873, 1008580720, 11652595461
OFFSET
0,2
FORMULA
Conjectures from R. J. Mathar, May 25 2010: (Start)
a(n) = 2*11^n+13^n/2+5*9^n-15*7^n/2;
a(n) = +40*a(n-1) -590*a(n-2) +3800*a(n-3) -9009*a(n-4).
G.f.: x*(21-476*x+2663*x^2) / ( (11*x-1)*(13*x-1)*(7*x-1)*(9*x-1) ). (End)
CROSSREFS
Sequence in context: A302876 A303524 A108495 * A324360 A323001 A152182
KEYWORD
nonn,more
AUTHOR
R. H. Hardin, suggested by R. J. Mathar in the Sequence Fans Mailing List, May 25 2010
STATUS
approved