A122037 Largest prime factor of number equal to the arithmetic mean of four successive primes.

3, 3, 5, 3, 11, 5, 19, 7, 23, 11, 5, 17, 3, 29, 17, 7, 3, 19, 5, 127, 139, 3, 149, 31, 11, 7, 181, 31, 13, 5, 43, 19, 29, 241, 19, 23, 13, 53, 5, 139, 97, 17, 13, 53, 37, 31, 11, 17, 11, 127, 43, 19, 7, 71, 431, 7, 149, 11, 79, 37, 163, 11, 127, 257, 41, 271, 23, 43, 113, 19, 3

Offset: 1

Author

Giovanni Teofilatto, Sep 14 2006

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A006530, A102655.

Programs

Mathematica

FactorInteger[ # ][[ -1, 1]] & /@ Select[Table[Sum[Prime[k], {k, n, n + 3}]/4, {n, 120}], IntegerQ] (* Ray Chandler, Sep 25 2006 *)
FactorInteger[#][[-1,1]]&/@Select[Mean/@Partition[Prime[Range[ 200]], 4,1], IntegerQ] (* Harvey P. Dale, May 21 2014 *)

Formula

a(n) = A006530(A102655(n)).

Extensions

Extended by Ray Chandler, Sep 25 2006