A175541 A007505 in binary.

10, 101, 1011, 10111, 101111, 10111111, 101111111, 1011111111111, 10111111111111111111, 101111111111111111111111111111111111, 1011111111111111111111111111111111111111

Offset: 1

Author

Juri-Stepan Gerasimov, Jun 24 2010

Keywords

• nonn
• base

Comments

Primes of the form 10, 101, 1011, 10111,..

Examples

			a(12)=101111111111111111111111111111111111111111111.
		

Programs

Mathematica

FromDigits/@Select[Table[PadRight[{1,0},n,1],{n,0,50}], PrimeQ[ FromDigits[ #,2]]&] (* Harvey P. Dale, Nov 12 2011 *)

Formula

A002235(n)=A091997(n)-A000012(n)=A000120(A007505(n))-A023416(A007505(n)).