A299213 Lucas-Carmichael numbers whose prime factors do not divide any smaller Lucas-Carmichael number.

399, 935, 565861139, 5778659039, 22824172799, 49569379679, 221511111527, 572531110799, 745012846679, 1034101753931, 1370873302991, 2170525568639, 2374771783151, 2621128819063, 3371253685379, 3720157305479, 5533009370111, 5850130431599, 8405935805119, 8454421987199

Offset

1,1

Comments

Also numbers whose number of occurrence in A253597 equals the number of their prime factors.

All known terms have only 3 prime factors. Does any term with more than 3 prime factors exist?

Links

Amiram Eldar, Table of n, a(n) for n = 1..105 (terms below 10^15, calculated from Daniel Suteu's file at A006972)

Example

565861139 = 193*1163*2521 and no smaller Lucas-Carmichael number is divisible by 193, 1163 or 2521.

Prog

(PARI) a=readvec("b006972.txt"); print1(399); for(b=2, 10000, e=true; f=factor(a[b]); for(d=1, #f[, 1], for(c=1, b-1, if(a[c]%f[d, 1]==0, e=false))); if(e==true, print1(", ", a[b])))

Crossrefs

Cf. A006972, A202562, A253597.

Sequence in context: A006972 A216925 A292573 * A396052 A206536 A292538

Adjacent sequences: A299210 A299211 A299212 * A299214 A299215 A299216

Keyword

nonn

Author

Tim Johannes Ohrtmann, Feb 05 2018

Extensions

a(10)-a(20) from Amiram Eldar, Mar 29 2026

Status

approved