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Primes in the products of consecutive prime-indexed primes + 2 or A080696(n) + 2.
2

%I #15 Jul 05 2024 08:13:03

%S 5,17,167,14093057717,16192486429745837,

%T 114681479899746991802547357477494807,

%U 12994174855450524638613469509299054674461271855442034674644855689971858721497

%N Primes in the products of consecutive prime-indexed primes + 2 or A080696(n) + 2.

%C These numbers, except for the first one, always end in 7.

%C The next term (a(8)) has 129 digits. - _Harvey P. Dale_, Apr 05 2019

%H Amiram Eldar, <a href="/A090886/b090886.txt">Table of n, a(n) for n = 1..12</a>

%t Select[FoldList[Times,Table[Prime[n],{n,Prime[Range[40]]}]]+2,PrimeQ] (* _Harvey P. Dale_, Apr 05 2019 *)

%o (PARI) piptorial2(n) = { y=1; for(x=1,n, v=prime(prime(x)); y*=v; if(isprime(y+2),print1(y+2",")) ) }

%Y Cf. A080696, A087400.

%K nonn

%O 1,1

%A _Cino Hilliard_, Feb 12 2004