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A173556 Triangle T(n,m) = (prime(n)-1)*(prime(m)- 1) mod 8 read by rows. 0
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 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Row sums are: 1, 6, 4, 14, 14, 4, 0, 18, 26, 4,...
LINKS
FORMULA
t(n,m)=Mod[(Prime[n] - 1)*(Prime[m] - 1), 8]
EXAMPLE
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;
MATHEMATICA
t[n_, m_] = Mod[(Prime[n] - 1)*(Prime[m] - 1), 8];
Table[Table[t[n, m], {m, 1, n}], {n, 1, 10}];
Flatten[%]
CROSSREFS
Sequence in context: A163089 A258371 A111172 * A247554 A198786 A176531
KEYWORD
nonn,tabl,easy
AUTHOR
Roger L. Bagula, Feb 21 2010
EXTENSIONS
Standardized nomenclature - the Assoc. Editors of the OEIS, Feb 24 2010
STATUS
approved

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Last modified March 2 08:59 EST 2024. Contains 370461 sequences. (Running on oeis4.)