OFFSET
1,1
COMMENTS
LINKS
Robert Israel, Table of n, a(n) for n = 1..1000
EXAMPLE
MAPLE
spf:= proc(n) local t; option remember; add(t[1]*t[2], t=ifactors(n)[2]) end proc:
select(t -> (spf(t+1) = spf(t)+1) and isprime(spf(t)^2 + 3*spf(t)+1), [$1..10^6]);
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Mar 21 2022
STATUS
approved