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A125113 Numbers n such that 2n-1, 4n-1, 8n-1, 16n-1, 32n-1 and 64n-1 are primes. 8

%I #11 Jan 20 2020 19:53:52

%S 45,31710,63570,202635,405405,534600,561330,589305,666945,799350,

%T 903045,979125,1082115,1122660,1164735,1303035,1424475,1620645,

%U 1669995,1892100,1981020,2044440,2164230,2222415,2329470,2332125,2447445,2448855

%N Numbers n such that 2n-1, 4n-1, 8n-1, 16n-1, 32n-1 and 64n-1 are primes.

%H Harvey P. Dale, <a href="/A125113/b125113.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[15*Range[200000], And @@ PrimeQ /@ ({2, 4, 8, 16, 32, 64}*# - 1) &] (* _Ray Chandler_, Nov 22 2006 *)

%t Select[15*Range[164000],AllTrue[# 2^Range[6]-1,PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Jan 20 2020 *)

%Y Cf. A006254, A124485, A124493, A124494, A124017, A124514, A124515, A124516.

%K nonn

%O 1,1

%A _Artur Jasinski_, Nov 22 2006

%E Extended by _Ray Chandler_, Nov 22 2006

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Last modified April 24 22:17 EDT 2024. Contains 371964 sequences. (Running on oeis4.)