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A232558 a(1)=5, q=a(n) is the smallest prime > a(n-1) such that q-2*n = p prime 3

%I

%S 5,7,11,13,17,19,31,47,59,61,83,97,109,131,137,139,173,193,211,233,

%T 239,241,257,271,277,281,283,307,389,397,409,431,433,457,467,491,523,

%U 563,569,571,653,661,673,701,709,733,821,823,859,887,911,967,983,991

%N a(1)=5, q=a(n) is the smallest prime > a(n-1) such that q-2*n = p prime

%C Conjecture: the sequence is infinite.

%C Remarks: the primes p appears in increasing order but with repetition, all the primes are not present in p,q.

%H Pierre CAMI, <a href="/A232558/b232558.txt">Table of n, a(n) for n = 1..10000</a>

%e 5-3=2 a(1)=5

%e 7-3=4 a(2)=7

%e 11-5=6 a(3)=11

%e 13-5=8 a(4)=13

%e 17-7=10 a(5)=17

%t a[1]=5;a[n_]:=a[n]=(For[k=a[n-1]+2,!(k>2n&&PrimeQ[k]&&PrimeQ[k-2n]),k++];k)

%Y Cf. A020483

%K nonn

%O 1,1

%A _Pierre CAMI_, Nov 26 2013

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Last modified July 1 10:51 EDT 2022. Contains 354970 sequences. (Running on oeis4.)