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 A233552 Odd integers k such that for every m >= 1 the numbers k*4^m - 1 have at least three prime factors, not necessarily distinct, and k*4^m - 1 has at least two-element covering set. 1
 361, 919, 1681, 1849, 2419, 2629, 3301, 5209, 5539, 5581, 6421, 7771, 8551, 9109, 9871, 10039, 10609, 10819, 11491, 13399, 13729, 13771, 14611, 15661, 15961, 16741, 17299, 18061, 18229, 18799, 19009, 19681, 21589, 21919, 21961, 22801, 24151, 24931, 25489 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Here an n-element covering set is a minimal set of n distinct primes such that at least one of these primes divides every integer in the sequence k*4^m - 1, m >= 1. - Arkadiusz Wesolowski, Jul 21 2021 LINKS Table of n, a(n) for n=1..39. CROSSREFS Sequence in context: A219340 A183997 A211822 * A176899 A361704 A302229 Adjacent sequences: A233549 A233550 A233551 * A233553 A233554 A233555 KEYWORD nonn AUTHOR Arkadiusz Wesolowski, Dec 12 2013 EXTENSIONS Name corrected by Arkadiusz Wesolowski, Jul 21 2021 STATUS approved

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Last modified May 29 15:14 EDT 2023. Contains 363042 sequences. (Running on oeis4.)