login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A082215 Numbers obtained in the concatenation of terms starting with the first term of A018238. 2
1, 121, 1213121, 121312141213121, 1213121412131215121312141213121, 121312141213121512131214121312161213121412131215121312141213121, 1213121412131215121312141213121612131214121312151213121412131217121312141213121512131214121312161213121412131215121312141213121 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Also called Zimin words.

a(n) is a palindrome for n<10; it is debatable whether a(n) can be called a Zimin word for n>=10 (see the Comments in A018238). - Danny Rorabaugh, Sep 26 2015

LINKS

Table of n, a(n) for n=1..7.

J. Cooper and D. Rorabaugh, Bounds on Zimin Word Avoidance, arXiv:1409.3080 [math.CO]; Congressus Numerantium, 222 (2014), 87-95.

L. J. Cummings and M. Mays, A one-sided Zimin construction, Electron. J. Combin. 8 (2001), #R27.

A. I. Zimin, Blocking sets of terms, Math. USSR Sbornik, 47 (1984), No. 2, 353-364.

FORMULA

The Zimin words are defined here by Z_1 = 1, Z_n = Z_{n-1}nZ_{n-1}. - Dmitry Kamenetsky, Sep 30 2006

MATHEMATICA

a = {1}; Do[w = IntegerDigits@ a[[n - 1]]; AppendTo[a, FromDigits@ Join[w, IntegerDigits@ n, w]], {n, 2, 7}]; a (* Michael De Vlieger, Sep 26 2015 *)

CROSSREFS

Cf. A018238, A123121.

See A001511 for another representation of this sequence of digits.

Sequence in context: A227301 A261364 A136094 * A123179 A245593 A053885

Adjacent sequences:  A082212 A082213 A082214 * A082216 A082217 A082218

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Apr 08 2003

EXTENSIONS

More terms from Joshua Zucker, May 08 2006

"Palindromes" replaced with "Numbers" in sequence name by Danny Rorabaugh, Sep 26 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified September 26 14:12 EDT 2017. Contains 292529 sequences.