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A076559
Greatest prime divisor of n-th interprime: (prime(n) + prime(n+1))/2.
1
2, 3, 3, 3, 5, 3, 7, 13, 5, 17, 13, 7, 5, 5, 7, 5, 2, 23, 3, 19, 3, 43, 31, 11, 17, 7, 3, 37, 5, 43, 67, 23, 3, 5, 11, 5, 11, 17, 11, 5, 31, 3, 13, 11, 41, 31, 5, 19, 11, 59, 5, 41, 127, 13, 19, 5, 137, 31, 47, 3, 5, 103, 13, 7, 3, 167, 19, 29, 13, 89, 11, 37, 47, 127, 193, 131, 19
OFFSET
2,1
LINKS
FORMULA
a(n) = A006530(A024675(n-1)). - R. J. Mathar, May 10 2023
MAPLE
A076559 := proc(n)
A006530((ithprime(n)+ithprime(n+1))/2) ;
end proc:
seq(A076559(n), n=2..120) ; # R. J. Mathar, May 10 2023
MATHEMATICA
gpf[n_] := FactorInteger[n][[-1, 1]]; p = Select[Range[405], PrimeQ]; gpf /@ ((p[[2 ;; -2]] + p[[3 ;; -1]])/2) (* Amiram Eldar, Aug 29 2019 *)
CROSSREFS
Cf. A071216.
Sequence in context: A359507 A366660 A241686 * A102601 A092308 A205394
KEYWORD
easy,nonn
AUTHOR
Zak Seidov, Oct 19 2002
STATUS
approved