The On-Line Encyclopedia of Integer Sequences (OEIS)

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A336752

The 'Look and Say' sequence of the concatenation of the prime numbers A033308.
(history; published version)

#21 by N. J. A. Sloane at Mon Aug 17 22:44:54 EDT 2020

STATUS

proposed

approved

#20 by Scott R. Shannon at Mon Aug 17 22:43:08 EDT 2020

STATUS

editing

proposed

#19 by Scott R. Shannon at Mon Aug 17 22:43:01 EDT 2020

EXAMPLE

a(9) = 3, a(110) = 1 as the primes '11' and '13' from the substring '1113'. which starts with three 1's.

STATUS

approved

editing

Discussion

Mon Aug 17

22:43

Scott R. Shannon: Fixing typo

#18 by N. J. A. Sloane at Sun Aug 16 14:06:35 EDT 2020

STATUS

proposed

approved

#17 by Scott R. Shannon at Sun Aug 16 03:41:36 EDT 2020

STATUS

editing

proposed

#16 by Scott R. Shannon at Sun Aug 16 03:41:16 EDT 2020

CROSSREFS

Cf. A033308, A005150, A001155, A056815, A000040, A033308.

#15 by Scott R. Shannon at Sun Aug 16 03:35:21 EDT 2020

NAME

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

#14 by Scott R. Shannon at Sun Aug 16 03:32:25 EDT 2020

COMMENTS

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

#13 by Scott R. Shannon at Sun Aug 16 03:32:07 EDT 2020

NAME

wip

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

COMMENTS

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

LINKS

J. H. Conway and Brady Haran, <a href="https://www.youtube.com/watch?v=ea7lJkEhytA">Look-and-Say Numbers</a> (2014), Numberphile video.

Wikipedia, <a href="http://en.wikipedia.org/wiki/Look-and-say_sequence">Look-and-say sequence</a>.

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.

a(9) = 3, a(1) = 1 as the primes '11' and '13' from the substring '1113'. which starts with three 1's.

CROSSREFS

Cf. A033308, A005150, A001155, A056815, A000040, A033308.

#12 by Scott R. Shannon at Sun Aug 16 02:33:35 EDT 2020

DATA

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