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%I #6 Dec 08 2018 04:10:52
%S 2,21,72,181,390,715
%N Scores for Part 2 of the n X n generalization of the Gordon Lee puzzle.
%C See A109943 and the references therein for more information.
%C 1192 and 1847 are lower bounds for the next terms a(7) and a(8).
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PrimeArray.html">Prime Array.</a>
%H Al Zimmermann's Programming Contests. Primal Squares: <a href="http://www.recmath.org/contest/description.php">The Problem</a>
%H Al Zimmermann's Programming Contests. Primal Squares: <a href="http://www.recmath.org/contest/BestSolutions1.php">Best grids for part 1 found during the contest.</a>
%H Al Zimmermann's Programming Contests. Primal Squares: <a href="http://www.recmath.org/contest/BestSolutions2.php">Part 2 solutions</a>
%e a(2)=21 is the "part 2" score for the matrix
%e 4 7
%e 3 1
%e which contains two single-digit primes and one even number (score: 2+1)
%e and 9 2-digit primes: 13,17,31,37,41,43,47,71,73 score(9*2); total = 3+18 = 21.
%Y Cf. A032529 = all primes in the 3 X 3 record matrix, A034720 = number of candidates to be checked for primality in an n X n matrix of single digits.
%K hard,more,nonn
%O 1,1
%A _Hugo Pfoertner_, Sep 21 2005
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