A388657 a(n) is the greatest prime factor of prime(n)^prime(n) + 1.

5, 7, 521, 911, 58367, 79301, 45957792327018709121, 870542161121, 1522029233, 5639663878716545087233, 2706690202468649, 129509177219632766702207249, 86113001092268374480278191141726032792032074455581281, 1140834804168935454622067377, 3543413924249049822089893, 114127661423703553269817046865907159894634137

Offset

1,1

Links

Hugo Pfoertner, Table of n, a(n) for n = 1..34

Status of 149^149+1 in factordb.com.

Formula

a(n) = A006530(A125137(n)).

a(n) = A007571(prime(n)).

Mathematica

a[n_] := FactorInteger[Prime[n]^Prime[n] + 1][[-1, 1]]; Array[a, 16] (* Amiram Eldar, Sep 19 2025 *)

Crossrefs

Cf. A006530, A007571, A051674, A125137, A214812, A388417.

Sequence in context: A059394 A176960 A114368 * A386079 A260830 A260827

Adjacent sequences: A388654 A388655 A388656 * A388658 A388659 A388660

Keyword

nonn

Author

Hugo Pfoertner, Sep 19 2025

Status

approved