A094068 - OEIS

%I #16 Nov 30 2022 13:30:46

%S 3,29,107,239,281,857,1061,1151,1619,1667,1721,2267,2339,2801,2999,

%T 3167,3257,3467,3557,4271,4337,4547,4799,4931,5279,5501,5849,5867,

%U 6359,6659,6689,7349,8009,8219,8231,8387,9857,10007,10859,13001,13691,15269,15971

%N Lessers of twin prime pairs whose greater has a prime prime index.

%H Amiram Eldar, <a href="/A094068/b094068.txt">Table of n, a(n) for n = 1..10000</a>

%e 107 is the lesser of twin prime pair (107,109) the prime index of 109 (the greater) is 29.

%t seq = {}; p = prv = 2; k = 1; Do[p = NextPrime[p]; k++; If[p == prv + 2 && PrimeQ[k], AppendTo[seq, prv]]; prv = p, {10^3}]; seq

%t Select[Partition[Prime[Range[2000]],2,1],#[[2]]-#[[1]]==2&&PrimeQ[PrimePi[ #[[2]]]]&] [[All,1]] (* _Harvey P. Dale_, Nov 30 2022 *)

%o (PARI) lista(n) = {forprime(x=2,n, y=prime(x)- 2; if(isprime(y),print1(y",")))}

%Y Cf. A001097, A001359, A006512, A096479.

%K nonn

%O 1,1

%A _Cino Hilliard_, May 31 2004

%E Offset corrected by _Amiram Eldar_, Dec 27 2019