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A054551
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Prime number spiral (clockwise, North spoke).
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9
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2, 3, 31, 107, 241, 443, 709, 1049, 1471, 1973, 2539, 3191, 3911, 4729, 5651, 6637, 7699, 8867, 10133, 11503, 12941, 14537, 16073, 17863, 19727, 21601, 23609, 25759, 27967, 30319, 32719, 35201, 37831, 40627, 43391, 46399, 49411, 52553, 55813
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OFFSET
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0,1
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COMMENTS
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Smallest prime in n-th shell of prime spiral.
8-spoke wheel overlays prime number spiral; hub is 2 in shell 0; 8 spokes radiate from this hub; this is North, clockwise.
Shell 1 comprises the primes 3 5 7 11 13 17 19 23; 3 is lowest, 23 is highest.
The wheel may be rotated, but the sequences though pointing in different directions, will remain the same.
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LINKS
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FORMULA
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EXAMPLE
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Begin a prime number spiral at zero, proceed clockwise, North.
The spiral with four terms in every spoke looks like this:
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227 101--103--107--109--113--127
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223 97 29---31---37---41 131
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211 89 23 3----5 43 137
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199 83 19 2 7 47 139
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197 79 17---13---11 53 149
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193 73---71---67---61---59 151
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191--181--179--173--167--163--157
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(End)
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MATHEMATICA
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Table[ Prime[4n^2 - 3n + 1], {n, 0, 40} ]
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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