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A110885 Lucas-Carmichael numbers that are not congruent to 11 (mod 12). 2
399, 5719, 20705, 80189, 120581, 162687, 482143, 663679, 1162349, 7274249, 8734109, 9486399, 10260809, 10397407, 14658349, 14970499, 25603599, 29010079, 32869759, 49412285, 77801359, 90393029, 95972799, 99467679, 105818129, 110066669, 125532329, 126325399 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

There are 9967 Lucas-Carmichael numbers less than 10^12, and all but 332 are congruent to 11 (mod 12).

LINKS

Robert G. Wilson v, Table of n, a(n) for n = 1..333

EXAMPLE

5719=7*19*43=7 mod 12.

MAPLE

with(numtheory); LC:=[]: for z from 1 to 1 do for m from 1 to 2000000 do n:=2*m+1; if not(isprime(n)) and issqrfree(n) then PF:=factorset(n); lcb:=true; for x in PF do if (n+1) mod (x+1) > 0 then lcb:=false fi od; if lcb then LC:=[op(LC), n]; fi; fi; #not od; #m od; #z select(proc(z) not(z mod 12 = 11) end, LC);

CROSSREFS

Cf. A006972.

Sequence in context: A292538 A065767 A166915 * A249408 A216928 A283384

Adjacent sequences:  A110882 A110883 A110884 * A110886 A110887 A110888

KEYWORD

nonn

AUTHOR

Walter Kehowski, Sep 19 2005

EXTENSIONS

a(10) onward from Robert G. Wilson v, Feb 12 2015

STATUS

approved

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Last modified November 27 07:28 EST 2021. Contains 349365 sequences. (Running on oeis4.)