

A344659


Lexicographically earliest sequence of distinct nonnegative terms on a square spiral such that each term forms no prime value in the eight sums when each term is added to each of its eight nearest neighbors.


4



0, 1, 8, 14, 4, 6, 9, 15, 20, 5, 7, 13, 2, 12, 10, 11, 16, 22, 18, 3, 17, 19, 25, 29, 28, 21, 23, 27, 31, 26, 24, 30, 32, 34, 35, 33, 36, 41, 40, 42, 39, 37, 38, 43, 45, 47, 49, 53, 57, 48, 51, 54, 61, 50, 44, 46, 52, 56, 58, 60, 59, 65, 55, 62, 63, 70, 64, 74, 66, 69, 67, 68, 72, 73, 77, 71, 75
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OFFSET

1,3


COMMENTS

.
36333534323024
 
41 161110122 26
   
40 22 4148 13 31
     
42 18 6 01 7 27
    
39 3 915205 23 .
   .
37 171925292821 .
 
3843454749535748
.


LINKS



EXAMPLE

The eight terms that are in contact with the initial zero are 1, 8, 14, 4, 6, 9, 15, 20: none of them is prime [forcing the sum a(k) + 0 to be nonprime, with k<9]; more generally, no term of the square spiral when added to any of its eight nearest neighbors sums to a prime.


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



