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 A292364 Composites m such that each prime factor p > m of 2^m - 1 is a primitive prime factor of 2^m - 1. 0
 4, 8, 9, 12, 24, 121 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS From A086251: "A prime factor of 2^n-1 is called primitive if it does not divide 2^r-1 for any r= sqrt(k) that is not in this sequence, then gpf(2^d-1) > d^2 >= k and k is not in this sequence. If S is complete, there are 15 possible choices of k, the largest of which is 121, and this sequence is complete. (End) LINKS FORMULA A002326((p-1)/2) = m for every prime factor p > m of 2^m - 1. PROG (PARI) lista(nn) = {forcomposite (m=1, nn, f = factor(2^m-1)[, 1]~; ok = 1; for (k=1, #f, p = f[k]; if ((p > m) && (znorder(Mod(2, p)) != m), ok = 0; break); ); if (ok, print1(m, ", ")); ); } \\ Michel Marcus, Nov 11 2017 CROSSREFS Cf. A002326, A060443, A086251. Sequence in context: A048944 A211658 A235054 * A071835 A308416 A010429 Adjacent sequences:  A292361 A292362 A292363 * A292365 A292366 A292367 KEYWORD nonn,more AUTHOR Thomas Ordowski, Sep 15 2017 STATUS approved

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Last modified April 5 20:15 EDT 2020. Contains 333260 sequences. (Running on oeis4.)