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 A253598 a(n) = least Lucas-Carmichael number which is divisible by b(n), where {b(n)} (A255602) is the list of all numbers which could be a divisor of a Lucas-Carmichael number. 3
 399, 399, 935, 399, 935, 2015, 935, 399, 399, 4991, 51359, 2015, 8855, 1584599, 9486399, 20705, 5719, 18095, 2915, 935, 399, 46079, 162687, 2015, 22847, 46079, 16719263, 8855, 12719, 7055, 935, 80189, 189099039, 104663, 20705, 482143, 196559, 60059, 30073928079, 90287, 8855, 31535 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(640) <= 2172140962024052891965613396799. - Daniel Suteu, Feb 25 2023 LINKS Daniel Suteu, Table of n, a(n) for n = 1..639 (first 95 terms from Tim Johannes Ohrtmann, terms 96..154 from Robert G. Wilson v) EXAMPLE a(12) = 8855 because this is the least Lucas-Carmichael number which is divisible by A255602(12) = 35. MATHEMATICA LucasCarmichaelQ[n_] := Block[{fi = FactorInteger@ n}, ! PrimeQ@ n && Times @@ (Last@# & /@ fi) == 1 && Plus @@ Mod[n + 1, 1 + First@# & /@ fi] == 0]; LucasCarmichaelQ[1] = False; fQ[n_] := Block[{fi = FactorInteger@ n}, ffi = First@# & /@ fi; Times @@ (Last@# & /@ fi) == 1 && Min@ Flatten@ Table[Mod[1 + ffi, i], {i, ffi}] > 0]; fQ[1] = True; fQ[2] = False; lcdv = Select[ Range@ 3204, fQ]; f[n_] := Block[{k = lcdv[[n]]}, d = 2k; While[ !LucasCarmichaelQ@ k, k += d]; k]; Array[f, 95] (* Robert G. Wilson v, Feb 11 2015 *) CROSSREFS Cf. A006972, A253597, A255602. Sequence in context: A235569 A261768 A274446 * A046013 A352360 A176911 Adjacent sequences: A253595 A253596 A253597 * A253599 A253600 A253601 KEYWORD nonn AUTHOR Tim Johannes Ohrtmann, Jan 05 2015 EXTENSIONS a(96) from Charles R Greathouse IV, Feb 12 2015 STATUS approved

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Last modified September 23 07:35 EDT 2023. Contains 365544 sequences. (Running on oeis4.)