OFFSET
1,1
EXAMPLE
2 and 3 in base 2 are 10 and 11 and concat(10,11) = 1011 is 11 in base 10.
4 and 5 in base 2 are 100 and 101 and concat(100,101) = 100101 is 37 in base 10.
MAPLE
with(numtheory): P:= proc(q) local a, b, c, n; a:=convert(q+1, binary, decimal); b:=convert(q, binary, decimal); c:=convert(b*10^(ilog10(a)+1)+a, decimal, binary); if isprime(c) then c; fi; end: seq(P(i), i=1..1000);
MATHEMATICA
Select[Map[FromDigits[Apply[Join, IntegerDigits[#, 2]], 2] &, Partition[Range@ 320, 2, 1]], PrimeQ] (* Michael De Vlieger, May 18 2017 *)
PROG
(PARI) lista(nn) = {for (n=1, nn, if (isprime(p=fromdigits(Vec(concat(binary(n), binary(n+1))), 2)), print1(p, ", "))); } \\ Michel Marcus, May 20 2017
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Paolo P. Lava, May 18 2017
STATUS
approved