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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 Adjacent sequences: A173553 A173554 A173555 * A173557 A173558 A173559 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 December 5 12:42 EST 2022. Contains 358586 sequences. (Running on oeis4.)