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A122415 Triangle T(n,k) for 1 < k < n read by rows, where T(n,k) = 1 if gcd(n,k) is prime, 0 otherwise. 1
0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
3,1
COMMENTS
Triangle defined in A122414 without first column and main diagonal.
LINKS
PROG
(PARI) {m=14; v=vector(m, x, vector(x)); for(n=1, m, for(k=1, n-1, if(isprime(gcd(n+2, k+1)), v[n][k]=1))); for(n=1, m, for(k=1, n, print1(v[n][k], ", ")))}
CROSSREFS
Cf. A122414.
Row sums are in A087625. [From Klaus Brockhaus, May 29 2009]
Sequence in context: A284745 A103588 A153638 * A241666 A324539 A324964
KEYWORD
nonn,tabl
AUTHOR
Klaus Brockhaus, Sep 03 2006
STATUS
approved

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Last modified July 22 12:58 EDT 2024. Contains 374499 sequences. (Running on oeis4.)