OFFSET
1,1
COMMENTS
2*n*prime(a(n))+prime(a(n)+1) and 2*n*prime(a(n))+prime(a(n)+2) are prime.
LINKS
Robert Israel, Table of n, a(n) for n = 1..603
MAPLE
f:= proc(n) local p, q, r, k;
p:= ithprime(n);
q:= ithprime(n+1);
r:= ithprime(n+2);
for k from 2 by 2 do
if isprime(k*p+q) and isprime(k*p+r) then return k fi
od
end proc:
V:= Vector(100): count:= 0:
for n from 2 while count < 100 do v:= A[n]/2;
if v <= 100 and V[v] = 0 then V[v]:= n; count:= count+1 fi
od:
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Dec 31 2020
STATUS
approved