All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars
 perplexus dot info

 Interesting numbers (Posted on 2011-06-07)
3, __, 5, 7, 11, 13, 17, __, 29, __, 47...
What numbers go in the blanks?

 See The Solution Submitted by Math Man Rating: 3.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
 Sloaneable (spoiler) | Comment 2 of 3 |

Doing a Sloane search on 5, 7, 11, 13, 17 yields only one that satisfies 3, __, 5, 7, 11, 13, 17, and that's A001605, the indices of prime Fibonacci numbers:

3, 4, 5, 7, 11, 13, 17, 23, 29, 43, 47, 83, 131, 137, 359, 431, 433, 449, 509, 569, 571, 2971, 4723, 5387, 9311, 9677, 14431, 25561, 30757, 35999, 37511, 50833, 81839, 104911, 130021, 148091, 201107, 397379, 433781, 590041, 593689, 604711, 931517, 1049897, 1285607, 1636007, ...

with the caveat that "Some of the larger entries may only correspond to probable primes."

 Posted by Charlie on 2011-06-07 16:43:27

 Search: Search body:
Forums (0)