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A334971 a(n) is the least prime p such that p+2 is divisible by n-th prime. 1

%I

%S 2,7,3,5,31,11,83,17,67,317,29,109,367,41,139,157,293,59,199,211,71,

%T 709,911,443,677,503,101,2459,107,337,379,653,409,137,743,149,1097,

%U 487,499,863,1609,179,571,191,983,197,631,1559,6581,227,1163,1193,239,751

%N a(n) is the least prime p such that p+2 is divisible by n-th prime.

%H Zak Seidov, <a href="/A334971/b334971.txt">Table of n, a(n) for n = 1..10000</a>

%e a(1) = 2 because 2+2=4 is divisible by 2 (1st prime),

%e a(2) = 7 because 7+2=9 is divisible by 3 (2nd prime),

%e a(3) = 3 because 3+2=5 is divisible by 5 (3rd prime).

%o (PARI) a(n) = my(p=2); while ((p+2) % prime(n), p=nextprime(p+1)); p; \\ _Michel Marcus_, May 18 2020

%Y Cf. A052147.

%K nonn

%O 1,1

%A _Zak Seidov_, May 18 2020

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Last modified September 19 12:50 EDT 2021. Contains 347556 sequences. (Running on oeis4.)