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A120456
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Antidiagonal triangular version of the modulo 15 prime multiplication table past n=3.
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0
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1, 2, 2, 4, 4, 4, 7, 8, 8, 7, 8, 14, 1, 14, 8, 11, 1, 13, 13, 1, 11, 13, 7, 2, 4, 2, 7, 13, 14, 11, 14, 11, 11, 14, 11, 14
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OFFSET
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0,2
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COMMENTS
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This modulo 15 of prime digit endings is important because it gives even odd prime types that appear in pairs: {1,4},{2,13},{7,8},{11,14}
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LINKS
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FORMULA
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b[n]={1, 2, 4, 7, 8, 11, 13, 14} T[n,m]=Mod[b[n]*b[m],15] a(n) = T[n,m]: antidiagonal form
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EXAMPLE
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Array looks like:
1, 2, 4, 7, 8, 11, 13, 14
2, 4, 8, 14, 1, 7, 11, 13
4, 8, 1, 13, 2, 14, 7, 11
7, 14, 13, 4, 11, 2, 1, 8
8, 1, 2, 11, 4, 13, 14, 7
11, 7, 14, 2, 13, 1, 8, 4
13, 11, 7, 1, 14, 8, 4, 2
14, 13, 11, 8, 7, 4, 2, 1
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MATHEMATICA
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Table[Mod[Prime[n], 15], {n, 1, 50}] a = {1, 2, 4, 7, 8, 11, 13, 14} b = Table[Mod[a[[n]]*a[[m]], 15], {n, 1, 8}, {m, 1, 8}] c = Table[Table[b[[n, l - n]], {n, 1, l - 1}], {l, 1, Dimensions[b][[1]] + 1}] Flatten[c]
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CROSSREFS
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KEYWORD
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nonn,tabf,fini
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AUTHOR
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STATUS
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approved
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