OFFSET
1,2
COMMENTS
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(2) = 189 as 189 is the smallest number such that 18911, 18913, 18917 and 18919 are all prime.
MAPLE
f:= proc(n) local R, k, p;
R:= map(`+`, [1, 3, 7, 9], 10*(n-1));
p:= 10^(ilog10(R[1])+1);
for k from 1 do
if map(t -> isprime(t+p*k), R) = [true, true, true, true] then return k fi
od
end proc:
map(f, [$1..60]); # Robert Israel, Jun 18 2017
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Sep 28 2003
EXTENSIONS
Corrected and extended by Ray G. Opao, Mar 23 2005
More terms from David Wasserman, Jul 27 2005
STATUS
approved