OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..187
EXAMPLE
a(3) = 1231 and k = 1.
MAPLE
dcat:= proc(L) local t, i;
t:= L[1];
for i from 2 to nops(L) do
t:= t*10^(1+ilog10(L[i]))+L[i]
od:
t
end proc:
f:= proc(n) local r, k, p;
for k from 1 do
p:= dcat([seq(r*k, r=1..n), 1]);
if isprime(p) then return p fi
od
end proc:
map(f, [$1..20]); # Robert Israel, Apr 30 2018
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 04 2003
EXTENSIONS
More terms from David Wasserman, Sep 13 2005
STATUS
approved