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A174953
Triangle read by rows: R(n,k) = prime(n) mod semiprime(k), 1<=k<=n.
0
2, 3, 3, 1, 5, 5, 3, 1, 7, 7, 3, 5, 2, 1, 11, 1, 1, 4, 3, 13, 13, 1, 5, 8, 7, 3, 2, 17, 3, 1, 1, 9, 5, 4, 19, 19, 3, 5, 5, 3, 9, 8, 2, 1, 23, 1, 5, 2, 9, 1, 14, 8, 7, 4, 3, 3, 1, 4, 1, 3, 1, 10, 9, 6, 5, 31, 1, 1, 1, 7, 9, 7, 16, 15, 12, 11, 4, 3, 1, 5, 5, 1, 13, 11, 20, 19, 16, 15, 8, 7, 6, 3, 1, 7, 3, 1, 13, 1, 21, 18, 17, 10, 9, 8, 5
OFFSET
1,1
EXAMPLE
The triangle starts as
2;
3, 3;
1, 5, 5;
3, 1, 7, 7;
3, 5, 2, 1, 11;
1, 1, 4, 3, 13, 13;
1, 5, 8, 7, 3, 2, 17;
3, 1, 1, 9, 5, 4, 19, 19;
3, 5, 5, 3, 9, 8, 2, 1, 23;
1, 5, 2, 9, 1, 14, 8, 7, 4, 3;
PROG
(Magma) IsSemiprime:=func< n | &+[ k[2]: k in Factorization(n) ] eq 2 >; splt:=38; T:=[ n: n in [2..splt] | IsSemiprime(n) ]; &cat[ [ NthPrime(n) mod T[k]: k in [1..n] ]: n in [1..#T] ]; // Klaus Brockhaus, Dec 02 2010
CROSSREFS
Sequence in context: A035516 A120428 A079950 * A298599 A138677 A193885
KEYWORD
nonn,tabl,easy
AUTHOR
STATUS
approved