

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
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OFFSET

1,2


COMMENTS

Row sums are: 1, 6, 4, 14, 14, 4, 0, 18, 26, 4,...


LINKS

Table of n, a(n) for n=1..106.


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



