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A173556
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Triangle T(n,m) = (prime(n)-1)*(prime(m)- 1) mod 8 read by rows.
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0
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1, 2, 4, 4, 0, 0, 6, 4, 0, 4, 2, 4, 0, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 4, 0, 4, 4, 0, 0, 4, 6, 4, 0, 4, 4, 0, 0, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 4, 0, 4, 4, 0, 0, 4, 4, 0, 4, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 4, 0, 4, 4, 0, 0, 4, 4, 0, 4, 0, 0, 4, 6
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OFFSET
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1,2
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COMMENTS
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Row sums are: 1, 6, 4, 14, 14, 4, 0, 18, 26, 4,...
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LINKS
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FORMULA
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t(n,m)=Mod[(Prime[n] - 1)*(Prime[m] - 1), 8]
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EXAMPLE
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The triangle (prime(n)-1)*(prime(m)-1) starts
1;
2,4 ;
4,8,16 ;
6,12,24,36 ;
10,20,40,60,100 ;
12,24,48,72,120,144 ;
16,32,64,96,160,192,256 ;
and reduced mod 8, T(n,m) starts
1;
2, 4;
4, 0, 0;
6, 4, 0, 4;
2, 4, 0, 4, 4;
4, 0, 0, 0, 0, 0;
0, 0, 0, 0, 0, 0, 0;
2, 4, 0, 4, 4, 0, 0, 4;
6, 4, 0, 4, 4, 0, 0, 4, 4;
4, 0, 0, 0, 0, 0, 0, 0, 0, 0;
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MATHEMATICA
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t[n_, m_] = Mod[(Prime[n] - 1)*(Prime[m] - 1), 8];
Table[Table[t[n, m], {m, 1, n}], {n, 1, 10}];
Flatten[%]
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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Standardized nomenclature - the Assoc. Editors of the OEIS, Feb 24 2010
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STATUS
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approved
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