OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
10141 is a term as a concatenation of prime(26)=101 followed by prime(13)=41.
MAPLE
a:=proc(k) local s, m: s:= [op(convert(ithprime(k), base, 10)), op(convert(ithprime(2*k), base, 10))]: m:=add(s[j]*10^(j-1), j=1..nops(s)): if not isprime(m) then RETURN(NULL) else RETURN(m) fi: end; seq(a(k), k=1..250); (C. Ronaldo)
MATHEMATICA
Select[Table[FromDigits[Flatten[IntegerDigits/@{Prime[2n], Prime[n]}]], {n, 250}], PrimeQ] (* Harvey P. Dale, Nov 17 2014 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 24 2003
EXTENSIONS
Corrected and extended by C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 25 2004
STATUS
approved