OFFSET
1,1
COMMENTS
a(n) = 2*prime(n)-1 if n is in A137288. - Robert Israel, May 19 2020
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
MAPLE
f:= n -> max(numtheory:-factorset(2*ithprime(n)-1)):
map(f, [$1..100]); # Robert Israel, May 19 2020
MATHEMATICA
a[n_] := FactorInteger[2*Prime[n]-1][[-1, 1]]; Array[a, 100] (* Amiram Eldar, Oct 27 2024 *)
PROG
(PARI) a(n) = {my(f = factor(2*prime(n)-1)); f[#f~, 1]; } \\ Amiram Eldar, Oct 27 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Name edited by Robert Israel, May 19 2020
STATUS
approved