A358179 Prime numbers with prime indices in A333244.
31, 709, 1787, 8527, 19577, 27457, 42043, 52711, 72727, 96797, 112129, 137077, 167449, 173867, 239489, 250751, 285191, 352007, 401519, 443419, 464939, 490643, 527623, 683873, 718807, 755387, 839483, 864013, 985151, 1021271, 1080923, 1128889, 1159901, 1278779, 1323503, 1342907, 1656649, 1693031
Offset: 1
Keywords
Examples
a(1) = prime(A333244(1)) = prime(11) = 31.
Links
- Michael P. May, Properties of Higher-Order Prime Number Sequences, Missouri J. Math. Sci. (2020) Vol. 32, No. 2, 158-170; and arXiv version, arXiv:2108.04662 [math.NT], 2021.
Programs
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Mathematica
b[n_] := b[n] = If[PrimeQ[n], 1+b[PrimePi[n]], 0]; a[n_] := a[n] = Module[{p}, p = If[n==1, 1, a[n-1]]; While[True, p = NextPrime[p]; If[#>3 && OddQ[#]&[b[p]], Break[]]]; p]; Array[a, 50]
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PARI
b(n)={my(k=0); while(isprime(n), k++; n=primepi(n)); k}; apply(x->prime(prime(prime(prime(x)))), select(n->b(n)%2, [1..500])) \\ Michel Marcus, Nov 18 2022
Comments