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A393501
Decimal expansion of the average dimensionless pairwise Manhattan distance between all points in a city minimizing this distance as a function of d for a symmetric boundary given by w(x) = +-(2 - |x|^d)^(1/d), |x| <= 2^(1/d).
2
6, 5, 0, 2, 4, 7, 6, 3, 4, 5, 5, 1, 4, 9, 0, 0, 5, 5, 7, 9, 4, 8, 7, 8, 0, 5, 5, 3, 9, 3, 1, 0, 7, 3, 4, 9, 2, 4, 3, 2, 0, 1, 7, 7, 2, 0, 5, 3, 4, 6, 6, 1, 1, 4, 0, 5, 0, 0, 8, 4, 4, 9, 8, 2, 4, 8, 4, 1, 0, 3, 2, 5, 5, 2, 5, 3, 1, 3, 5, 6, 3, 6, 3, 3, 5, 0, 4, 3, 3, 2, 3
OFFSET
0,1
COMMENTS
See Bender et al. for more information.
This approximation is by 2.6*10^(-6) worse than the true minimum given by A393500.
LINKS
Carl M. Bender, Michael A. Bender, Erik D. Demaine and Sándor P. Fekete, What is the optimal shape of a city?, Journal of Physics A: Mathematical and General, Volume 37, Number 1, 2014. Alternative link. (3.4, page 151)
EXAMPLE
0.6502476345514900557948780553931073492432...
PROG
(PARI) {my(A(d, a)=2*a^2*gamma(1/d)^2/(d*gamma(2/d)), M(d, a)=64*a^5 * intnum(x=0, 1, x*(1-x^d)^(1/d) * intnum(u=0, x, (1-u^d)^(1/d))), f(d) = M(d, 1)*A(d, 1)^(-5/2)); f(solve(x=1.815, 1.816, f'(x)))}
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Hugo Pfoertner, Feb 17 2026
STATUS
approved