A336752 - OEIS

A336752

The 'Look and Say' sequence of the concatenation of the prime numbers A033308.

1, 2, 1, 3, 1, 5, 1, 7, 3, 1, 1, 3, 1, 1, 1, 7, 1, 1, 1, 9, 1, 2, 1, 3, 1, 2, 1, 9, 1, 3, 1, 1, 1, 3, 1, 7, 1, 4, 1, 1, 1, 4, 1, 3, 1, 4, 1, 7, 1, 5, 1, 3, 1, 5, 1, 9, 1, 6, 1, 1, 1, 6, 2, 7, 1, 1, 1, 7, 1, 3, 1, 7, 1, 9, 1, 8, 1, 3, 1, 8, 2, 9, 1, 7, 1, 1, 1, 0, 2, 1, 1, 0, 1, 3, 1, 1, 1, 0, 1, 7

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Concatenate all the decimal prime numbers, see A033308, then describe the resulting infinite string using the 'Look and Say' method of A005150.

LINKS

Table of n, a(n) for n=1..100.

J. H. Conway and Brady Haran, Look-and-Say Numbers (2014), Numberphile video.

Wikipedia, Look-and-say sequence.

EXAMPLE

The concatenation of the primes starts "23571113171923293137...".

a(1) = 1, a(2) = 2 as there is one '2' at the start of the string.