A118328 Integer lengths of Catalan-primes: numbers n such that the concatenation of the first n decimal digits of Catalan's constant is prime.

52, 276, 25477

Offset

1,1

Links

Table of n, a(n) for n=1..3.

Eric Weisstein's World of Mathematics, Catalan's Constant Digits

Eric Weisstein's World of Mathematics, Constant Primes

Eric Weisstein's World of Mathematics, Integer Sequence Primes

Example

C = 0.915965594177..., so a(1) = 52 (the 52-digit number 915965...6721 is the 1st prime in the digit string).

Crossrefs

Cf. A006752, A118329.

Sequence in context: A252335 A230533 A235654 * A079414 A270769 A281396

Adjacent sequences: A118325 A118326 A118327 * A118329 A118330 A118331

Keyword

nonn,more,bref,base

Author

Eric W. Weisstein, Apr 24 2006

Extensions

a(3) = 25477 from Eric W. Weisstein, May 05 2006

Edited by Charles R Greathouse IV, Apr 27 2010

Status

approved