OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(4) = 19 =prime(8) and prime(8) followed by prime(8-4) =197 is prime.
MAPLE
f:= proc(n) local p, k, q, d;
p:= ithprime(n);
for k from n+1 do
p:= nextprime(p);
q:= ithprime(k-n);
d:= ilog10(q)+1;
if isprime(p*10^d+q) then return p fi
od
end proc:
map(f, [$1..100]); # Robert Israel, Dec 13 2017
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 24 2003
EXTENSIONS
More terms from David Wasserman, Oct 13 2005
STATUS
approved