login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A137745 Number of different strings of length n obtained from "abcde" by iteratively duplicating any substring. 4
0, 0, 0, 0, 0, 1, 5, 19, 66, 218, 700, 2218, 6997, 22064, 69662, 220395, 699090, 2224114, 7098773, 22733498 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,7

COMMENTS

See A137743 for more comments.

LINKS

Table of n, a(n) for n=0..19.

Index entries for doubling substrings

EXAMPLE

a(k) = 0 for k<5, since no shorter string can be obtained by duplicating a substring.

a(5) = # { abcde }, a(6) = # { aabcde, abbcde, abccde, abcdde, abcdee },

a(7) = # { aaabcde, aabbcde, aabccde, aabcdde, aabcdee, ababcde, abbbcde, abbccde, abbcdde, abbcdee, abcbcde, abcccde, abccdde, abccdee, abcdcde, abcddde, abcddee, abcdede, abcdeee }

PROG

(PARI) A135473(13, 5) /* function defined in A137743...*/

CROSSREFS

Cf. A137740-A137743, A135473, A137744-A137748.

Sequence in context: A239618 A124806 A059509 * A005021 A067325 A273599

Adjacent sequences:  A137742 A137743 A137744 * A137746 A137747 A137748

KEYWORD

more,nonn

AUTHOR

M. F. Hasler, Feb 10 2008

EXTENSIONS

a(14)-a(19) from Lars Blomberg, Jan 12 2013

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 4 21:25 EDT 2020. Contains 333238 sequences. (Running on oeis4.)