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A234852
Indices k of primes p=prime(k) such that prime(p)-p+1 is prime.
3
1, 2, 3, 4, 6, 7, 9, 11, 13, 14, 18, 20, 23, 24, 27, 29, 34, 36, 40, 42, 46, 47, 48, 53, 58, 59, 60, 62, 63, 64, 66, 68, 70, 71, 73, 90, 95, 100, 103, 105, 110, 121, 122, 127, 128, 132, 133, 134, 141, 143, 144, 153, 155, 156, 162
OFFSET
1,2
FORMULA
a(n) = PrimePi(A234695(n)), PrimePi = A000720.
MATHEMATICA
Select[Range[200], PrimeQ[Prime[Prime[#]]-Prime[#]+1]&] (* Harvey P. Dale, Jul 14 2024 *)
PROG
(PARI) for(k=1, 999, isprime(prime(p=prime(k))-p+1)&&print1(k", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
M. F. Hasler, Dec 31 2013
STATUS
approved