A008997 - OEIS

%I #23 Aug 13 2020 18:31:36

%S 0,0,0,0,1,1,1,1,2,2,2,3,3,4,6,6,7,9,10,11

%N Orchard problem with 5 trees in a row (may not have all been proved optimal).

%C Berloquin shows that a(21) >= 12.

%D S. A. Burr, B. Grünbaum and N. J. A. Sloane, The Orchard Problem, Geometriae Dedicata, 2 (1974), 397-424.

%D M. Gardner, Time Travel and Other Mathematical Bewilderments. Freeman, NY, 1988, Chap. 22.

%H P. Berloquin, <a href="/A008997/a008997.jpg">a(21) >= 12</a> (from an article in Jeux & Strategies from 1983 - see Fig. 13)

%H S. A. Burr, B. Grünbaum and N. J. A. Sloane, <a href="http://neilsloane.com/doc/ORCHARD/orchard.html">The Orchard Problem</a>, Geometriae Dedicata, 2 (1974), 397-424.

%H Erich Friedman, <a href="https://erich-friedman.github.io/packing/trees/">Table of values and bounds for up to 21 trees</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Orchard-PlantingProblem.html">Orchard-Planting Problem</a>

%Y Cf. A003035, A006065.

%K nonn,nice,more

%O 1,9

%A _N. J. A. Sloane_