OFFSET
1,1
LINKS
K. D. Bajpai, Table of n, a(n) for n = 1..1461
EXAMPLE
pi(6) = 3: prime(6) = 13. Concatenation of 3 and 13 gives 313 which is prime and appears in the sequence.
pi(8) = 4: prime(6) = 19. Concatenation of 4 and 19 gives 419 which is prime and appears in the sequence.
MAPLE
with(StringTools): with(numtheory): KD := proc() local a, b, d; a:=pi(n); b:=ithprime(n); d:=parse(cat(a, b)); if isprime (d) then RETURN (d); fi; end: seq(KD(), n=1..300);
MATHEMATICA
Select[Table[FromDigits[Flatten[{IntegerDigits[PrimePi[n]], IntegerDigits[Prime[n]]}]], {n, 100}], PrimeQ] (* Alonso del Arte, Jan 28 2014 *)
CROSSREFS
KEYWORD
nonn,base,less
AUTHOR
K. D. Bajpai, Jan 28 2014
STATUS
approved