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A065698 Numbers m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,61. 4

%I #13 Oct 17 2019 16:20:06

%S 5580,19488,22050,86466,140268,173208,177966,227010,233598,265806,

%T 273126,355110,395736,402690,432336,476988,486138,550188,578370,

%U 588618,754416,788088,844086,1044288,1092600,1204596,1217406,1386498,1415778,1446888,1463358,1563276,1566936,1599876

%N Numbers m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,61.

%H Amiram Eldar, <a href="/A065698/b065698.txt">Table of n, a(n) for n = 1..10000</a>

%F am+1, bm+1, cm+1 are primes and am|(N-1), bm|(N-1), cm|(N-1).

%t CarmichaelNbrQ[n_] := ! PrimeQ@n && Mod[n, CarmichaelLambda@ n] == 1; Select[ Range@ 1600000, PrimeQ[# +1] && PrimeQ[2# +1] && PrimeQ[61# +1] && CarmichaelNbrQ[(# +1) (2# +1) (61# +1)] &] (* _Robert G. Wilson v_, Jul 31 2017 *)

%Y Cf. A064238-A064262, A065695-A065703, A087788.

%K nonn

%O 1,1

%A Harvey Dubner (harvey(AT)dubner.com), Nov 14 2001

%E a(8) onward from _Robert G. Wilson v_, Jul 31 2017

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Last modified June 22 15:06 EDT 2024. Contains 373587 sequences. (Running on oeis4.)