A158619 Twin prime pairs concatenated in binary representation.

11101, 101111, 10111101, 1000110011, 1110111111, 101001101011, 111011111101, 10001111001001, 11001011100111, 11010111101101, 1000100110001011, 1001010110010111, 1011001110110101, 1011111111000001, 1100010111000111

Offset: 1

Author

Jonathan Vos Post, Mar 22 2009

Keywords

• base
• easy
• nonn

Comments

Binary analog of A095958.

Examples

			a(1) = 11101 because 11_2 = lower of first twin prime pair = 3, and 101_2 = higher of first twin prime pair = 5.
		

Crossrefs

Cf. A001359, A006512, A007088, A045533, A095958.

Programs

Maple

A001359 := proc(n) option remember ; if n = 1 then 3; else a := nextprime(procname(n-1)) ; while not isprime(a+2) do a := nextprime(a) ; od: RETURN(a) ; fi: end: A006512 := proc(n) A001359(n)+2 ; end: A007088 := proc(n) bdgs := convert(n,base,2) ; add( op(i,bdgs)*10^(i-1),i=1..nops(bdgs)) ; end: cat2 := proc(a,b) bdgs := max(1, 1+ilog10(b)) ; a*10^bdgs+b ; end: A158619 := proc(n) cat2(A007088(A001359(n)),A007088(A006512(n))) ; end: seq(A158619(n),n=1..30) ; # R. J. Mathar, Apr 16 2009

Formula

a(n) = A007088(A001359(n)) CONCATENATE A007088(A006512(n)) = A007088(A001359(n)) CONCATENATE A007088(A001359(n)+2).

Extensions

More terms from R. J. Mathar, Apr 16 2009