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A185145 Smallest average of twin prime pairs s such that n*s is also average of twin prime pairs. 3

%I

%S 4,6,4,18,6,12,6,30,12,6,18,6,150,30,4,12,6,4,12,12,42,30,6,18,6,12,4,

%T 270,12,6,42,6,6,30,12,12,180,6,60,6,30,150,30,30,4,18,6,4,18,12,42,6,

%U 150,30,12,60,4,6,18,4,462,180,1230,18,30,108,60,180,12

%N Smallest average of twin prime pairs s such that n*s is also average of twin prime pairs.

%C Probably for all n>1 and also for all average s there are at least an average n*s. Note that this is equivalent to the Twin Prime Conjecture. Verified n to 10^7. First consecutive averages: 4 to 34260.

%H G. C. Greubel, <a href="/A185145/b185145.txt">Table of n, a(n) for n = 1..5000</a>

%F a(n) = A014574(j) if n*A014574(j) = A014574(k).

%e A014574(12) = 150, then 13*150 = 1950 = A014574(60).

%t t=Select[Table[Prime[n] + 1, {n, 10^4}], PrimeQ[#1 + 1] & ]; Table[s:=t[[m]]; m=1; While[!PrimeQ[n*s-1] || !PrimeQ[n*s+1], m++]; s, {n,1,100}]

%Y Cf. A066388, A014574.

%K nonn

%O 1,1

%A _Manuel Valdivia_, Mar 12 2012

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Last modified July 15 20:00 EDT 2019. Contains 325056 sequences. (Running on oeis4.)