|
|
A221369
|
|
A two-digit Look-and-Say sequence starting with 13: each term summarizes the increasing two-digit substrings of the previous term.
|
|
9
|
|
|
13, 113, 111113, 411113, 311113141, 311113114231141, 511113214123331141142, 511112113314121123131132233241142151, 711312313214115321122223124331232233241142251, 411412213214115221522423224125431432233241142143151153171
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
COMMENTS
|
a(22) is the first term containing a zero; this is due to the fact that a(21) is the first term having exactly 10 occurrences of a two-digit number, namely 10 x 42.
|
|
LINKS
|
|
|
EXAMPLE
|
a(0) = 11: 1 x 13 --> a(1) = 113;
a(1) = 113: 1 x 11 and 1 x 13 --> a(2) = 111113;
a(2) = 111113: 4 x 11 and 1 x 13 --> a(3) = 411113;
a(3) = 411113: 3 x 11, 1 x 13 and 1 x 41 --> a(4) = 311113141.
|
|
PROG
|
(Haskell) See Link.
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|