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

%I

%S 0,0,0,0,0,1,5,19,66,218,700,2218,6997,22064,69662,220395,699090,

%T 2224114,7098773,22733498

%N Number of different strings of length n obtained from "abcde" by iteratively duplicating any substring.

%C See A137743 for more comments.

%H <a href="/index/Do#repeat">Index entries for doubling substrings</a>

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

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

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

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

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

%K more,nonn

%O 0,7

%A _M. F. Hasler_, Feb 10 2008

%E a(14)-a(19) from _Lars Blomberg_, Jan 12 2013

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 May 31 05:50 EDT 2020. Contains 334747 sequences. (Running on oeis4.)