OFFSET
1,1
COMMENTS
Numbers m such that A099776(m) is a semiprime. - Michel Marcus, Nov 17 2022
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..65536
MAPLE
a:= proc(n) local k; for k from 1+`if`(n=1, 0, a(n-1))
while (t-> isprime(t) or numtheory[bigomega](t)
>2)(2*k*(k+1)+1) do od: k
end:
seq(a(n), n=1..70); # Alois P. Heinz, Aug 01 2019
MATHEMATICA
Select[Range[1000], PrimeOmega[#^2 + (#+1)^2] == 2&] (* Jean-François Alcover, Nov 17 2022 *)
PROG
(PARI) isok(m) = bigomega(m^2 + (m+1)^2) == 2; \\ Michel Marcus, Nov 17 2022
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jason Earls, Jun 25 2005
STATUS
approved