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 A122414 Triangle T(n,k) for 1 <= k <= n read by rows, where T(n,k) = 1 if gcd(n,k) is prime, 0 otherwise. 2
 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS First column is all zeros, main diagonal is A010051 (characteristic function of primes). LINKS PROG (PARI) {m=14; v=vector(m, x, vector(x)); for(n=1, m, for(k=1, n, if(isprime(gcd(n, k)), v[n][k]=1))); for(n=1, m, for(k=1, n, print1(v[n][k], ", ")))} CROSSREFS Cf. A010051, A122415. Row sums are in A117494. [From Klaus Brockhaus, May 29 2009] Sequence in context: A272664 A074937 A143518 * A288216 A189628 A289239 Adjacent sequences:  A122411 A122412 A122413 * A122415 A122416 A122417 KEYWORD nonn,tabl AUTHOR Klaus Brockhaus, Sep 03 2006 STATUS approved

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Last modified April 17 02:14 EDT 2021. Contains 343059 sequences. (Running on oeis4.)