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A285691 a(1) = 2; a(n + 1) = smallest prime > a(n) such that a(n + 1) - a(n) is the product of six primes. 4

%I #11 Nov 28 2019 22:52:09

%S 2,1217,1361,1601,1697,1913,2129,2273,2417,2633,2729,2953,3049,3209,

%T 3433,3529,3593,3833,3929,4073,4217,4441,4657,4721,4817,5153,5297,

%U 5393,5717,5813,6029,6173,6269,6829,7069,7213,7309,7549,7789

%N a(1) = 2; a(n + 1) = smallest prime > a(n) such that a(n + 1) - a(n) is the product of six primes.

%C First differences: 1215, 144, 240, 96, 216, 216, 144, 144, 216, 96, 224, 96, 160, 224, 96, 64, 240, 96, 144, 144, ...

%H Robert Israel, <a href="/A285691/b285691.txt">Table of n, a(n) for n = 1..10000</a>

%p A[1]:= 2: p:= 2: n:= 1:

%p while n < 60 do

%p p:= nextprime(p);

%p if numtheory:-bigomega(p-A[n]) = 6 then n:= n+1; A[n]:= p;

%p fi

%p od:

%p seq(A[i],i=1..60); # _Robert Israel_, Nov 28 2019

%t NestList[Module[{p = NextPrime@ #}, While[PrimeOmega[p - #] != 6, p = NextPrime@ p]; p] &, 2, 38] (* _Michael De Vlieger_, Apr 25 2017 *)

%Y Cf. A255609, A285688, A285689, A285690.

%K nonn

%O 1,1

%A _Zak Seidov_, Apr 25 2017

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Last modified July 6 05:32 EDT 2024. Contains 374034 sequences. (Running on oeis4.)