OFFSET

1,1

COMMENTS

Primes of the form 2*A070087(n)+1 for some n. - Charles R Greathouse IV, Dec 22 2022

Conjecture: this sequence is of positive relative density in the primes, perhaps even 1/2. - Charles R Greathouse IV, Dec 22 2022

LINKS

Karl Hovekamp, Table of n, a(n) for n = 1..39328

EXAMPLE

a(1)=7 because the largest prime divisor of 6 is greater than the largest prime divisor of 8.

MAPLE

filter:= p -> isprime(p) and max(numtheory:-factorset(p-1)) > max(numtheory:-factorset(p+1)):

select(filter, [seq(i, i=3..1000, 2)]); # Robert Israel, Jan 15 2024

MATHEMATICA

Select[Prime@Range[2, 107], If[FactorInteger[#-1][[-1, 1]]>FactorInteger[#+1][[-1, 1]], True]&] (* James C. McMahon, Jan 15 2024 *)

CROSSREFS

KEYWORD

nonn

AUTHOR

Hugo Pfoertner, Feb 19 2005

STATUS

approved