A328445 a(n) is the smallest prime p such that n = Omega(p^n - 2) = Omega(p^n + 2) where Omega = A001222.
5, 11, 127, 401, 1487, 1153, 6199, 10301, 22193, 72277, 1301423
Offset: 1
Examples
5 is a term of a(1) because 1 = Omega(5) = Omega(7), 11 is a term of a(2) because 2 = Omega(119) = Omega(123).
Programs
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Mathematica
a[n_] := Module[{p = 2}, While[PrimeOmega[p^n - 2] != n || PrimeOmega[p^n + 2] != n, p = NextPrime[p]]; p]; Array[a, 10] (* Amiram Eldar, Oct 15 2019 *) -
PARI
a(n) = {my(p=3); while (! ((bigomega(p^n-2) == n) && (bigomega(p^n+2) == n)), p = nextprime(p+1)); p;} \\ Michel Marcus, Oct 17 2019
Extensions
a(11) from Daniel Suteu and Giovanni Resta, Nov 07 2019