OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3) = 34 is a term because 34 = 2 * 17, 34 + 1 = 35 = 5 * 7 and 2 * 34 + 1 = 69 = 3 * 23 all have 2 prime factors.
MAPLE
filter:= proc(n) local t; uses numtheory; t:= bigomega(n); t = bigomega(n+1) and t = bigomega(2*n+1) end proc:
select(filter, [$1..10000]);
MATHEMATICA
s = {}; Do[If[PrimeOmega[k] == PrimeOmega[k + 1] == PrimeOmega[2 k + 1], AppendTo[s, k]], {k, 1000}]; s
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov and Robert Israel, Jan 28 2024
STATUS
approved