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A230746 Carmichael numbers of the form (30*k + 1)*(120*k + 1)*(150*k + 1), where 30*k + 1, 120*k + 1 and 150*k + 1 are all primes. 2
68154001, 3713287801, 63593140801, 122666876401, 193403531401, 227959335001, 246682590001, 910355497801, 4790779641001, 5367929037001, 6486222838801, 24572944746001, 25408177226401, 27134994772801, 55003376283001, 63926508701401, 108117809748001, 112614220996801 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Carmichael Number

Index entries for sequences related to Carmichael numbers

Index entries for sequences related to pseudoprimes

FORMULA

(A007304 INTERSECT A157956) INTERSECT A230722.

MATHEMATICA

carmQ[n_] := CompositeQ[n] && Divisible[n - 1, CarmichaelLambda[n]]; v = {30, 120, 150}; Times @@ (v*# + 1) & /@ Select[Range[1000], AllTrue[(w = v*# + 1), PrimeQ] && carmQ[Times @@ w] &] (* Amiram Eldar, Nov 11 2019 *)

PROG

(MAGMA) [n : k in [1..593 by 2] | IsPrime(a) and IsPrime(b) and IsPrime(c) and IsOne(n mod CarmichaelLambda(n)) where n is a*b*c where a is 30*k+1 where b is 120*k+1 where c is 150*k+1]

CROSSREFS

Subsequence of A083739 and of A230722.

Cf. A002997, A007304, A157956.

Sequence in context: A183707 A256274 A158890 * A084071 A251615 A321706

Adjacent sequences:  A230743 A230744 A230745 * A230747 A230748 A230749

KEYWORD

nonn

AUTHOR

Arkadiusz Wesolowski, Oct 29 2013

STATUS

approved

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Last modified January 26 15:47 EST 2021. Contains 340439 sequences. (Running on oeis4.)