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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: A132151 A103588 A153638 * A109017 A110161 A134667 Adjacent sequences:  A122412 A122413 A122414 * A122416 A122417 A122418 KEYWORD nonn,tabl AUTHOR Klaus Brockhaus, Sep 03 2006 STATUS approved

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