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A111128

Scores for Part 2 of the n X n generalization of the Gordon Lee puzzle.

2, 21, 72, 181, 390, 715

OFFSET

1,1

COMMENTS

See A109943 and the references therein for more information.

1192 and 1847 are lower bounds for the next terms a(7) and a(8).

LINKS

Eric Weisstein's World of Mathematics, Prime Array.

Al Zimmermann's Programming Contests. Primal Squares: The Problem

Al Zimmermann's Programming Contests. Primal Squares: Best grids for part 1 found during the contest.

Al Zimmermann's Programming Contests. Primal Squares: Part 2 solutions

EXAMPLE

a(2)=21 is the "part 2" score for the matrix

4 7

3 1

which contains two single-digit primes and one even number (score: 2+1)

and 9 2-digit primes: 13,17,31,37,41,43,47,71,73 score(9*2); total = 3+18 = 21.

CROSSREFS

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.

KEYWORD

hard,more,nonn

AUTHOR

STATUS

approved

URL: https://oeis.org/A111128