A158619 Twin prime pairs concatenated in binary representation.

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

Offset

1,1

Comments

Binary analog of A095958.

Links

Table of n, a(n) for n=1..15.

Formula

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

Example

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

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

Crossrefs

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

Sequence in context: A235440 A235405 A360034 * A367815 A094324 A347911

Adjacent sequences: A158616 A158617 A158618 * A158620 A158621 A158622

Keyword

base,easy,nonn

Author

Jonathan Vos Post, Mar 22 2009

Extensions

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

Status

approved