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A236769
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Numbers n such that lpf(2^n -1) < lpf(2^lpf(n) -1).
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3
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55, 77, 161, 169, 221, 275, 299, 323, 377, 385, 391, 437, 481, 493, 539, 551, 559, 605, 611, 629, 689, 697, 703, 715, 731, 779, 793, 799, 817, 847, 893, 901, 923, 935, 949, 1001, 1007, 1027, 1045, 1073, 1079, 1121, 1127, 1147, 1159, 1241, 1265, 1271, 1273, 1309
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OFFSET
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1,1
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COMMENTS
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The numbers n for which A049479(n) < A049479(lpf(n)), where lpf(n) = A020639(n). All other n satisfy the equality (in particular all primes).
All terms are odd and composite. - Chai Wah Wu, Oct 04 2019
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LINKS
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PROG
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(PARI) lpf(n) = vecmin(factor(n)[, 1]);
lista() = {my(vlpfmp = readvec("A049479.log")); for (i=2, #vlpfmp, if (vlpfmp[i] < vlpfmp[lpf(i)], print1(i, ", ")); ); } \\ Michel Marcus, Jan 31 2014
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CROSSREFS
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Cf. A049479 (a question in the third comment).
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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