A119343 Theodorus primes: primes formed from the concatenation of the initial decimal digits of Theodorus's constant, sqrt(3).

17, 173, 1732050807568877293

Offset: 1

Author

Eric W. Weisstein, May 15 2006

Keywords

• nonn
• base

Comments

The next term (a(4)) has 111 digits. - Harvey P. Dale, Oct 24 2014

Examples

			sqrt(3) = 1.732050807568877..., 17, the concatenation of the first 2 decimal digits, is prime, so a(1) = 17.
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..6
• Eric Weisstein's World of Mathematics, Integer Sequence Primes.

Crossrefs

Cf. A002194, A119344.

Programs

Mathematica

nn=300;With[{ds3=RealDigits[Sqrt[3],10,nn][[1]]},Select[ Table[ FromDigits[ Take[ds3,n]],{n,nn}],PrimeQ]] (* Harvey P. Dale, Oct 24 2014 *)

Extensions

Edited by Charles R Greathouse IV, Apr 27 2010