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 A236769 Numbers n such that lpf(2^n -1) < lpf(2^lpf(n) -1). 3
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS 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 LINKS Chai Wah Wu, Table of n, a(n) for n = 1..111 PROG (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 CROSSREFS Cf. A049479 (a question in the third comment). Sequence in context: A050781 A060260 A152080 * A119224 A135984 A140377 Adjacent sequences:  A236766 A236767 A236768 * A236770 A236771 A236772 KEYWORD nonn,more AUTHOR Thomas Ordowski, Jan 31 2014 EXTENSIONS More terms from Michel Marcus, Jan 31 2014 More terms from Chai Wah Wu, Oct 04 2019 STATUS approved

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Last modified December 10 12:25 EST 2019. Contains 329895 sequences. (Running on oeis4.)