OFFSET
1,1
COMMENTS
All terms are even.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
a(3) = 166 is a term because the 166th prime is 983, and 166 = 2 * 83, 983 - 166 = 817 = 19 * 43, and 983 + 166 = 1149 = 3 * 383 are all semiprimes.
MAPLE
p:= 1: R:= NULL: count:= 0:
for k from 2 by 2 while count < 100 do
p:= nextprime(nextprime(p));
if isprime(k/2) and numtheory:-bigomega(k+p) = 2 and numtheory:-bigomega(p-k) = 2 then count:= count+1; R:= R, k fi
od:
R;
MATHEMATICA
s = {}; Do[If[{2, 2, 2} == PrimeOmega[{k, Prime[k] + k, Prime[k] - k}], AppendTo[s, k]], {k, 4, 10000}]; s
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov and Robert Israel, Dec 31 2023
STATUS
approved