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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A279626 Number of palindromes over an alphabet of size 4 of length 2n+1 having no (3/2)+ powers. 0
 4, 12, 24, 48, 120, 240, 480, 1104, 2448, 5376, 12048, 27456, 61704, 140664 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS A (3/2)+ power is a word of the form xx', where x' is a prefix of x and |x'| > |x|/2.  Every odd length (2n+1) is guaranteed to have at least one such palindrome. LINKS EXAMPLE For n = 2 the possibilities are {01210, 01310, 02120, 02320, 03130, 03230} and their images under permutations of the alphabet. CROSSREFS Cf. A279611, A279625. Sequence in context: A132477 A102651 A102652 * A238607 A143270 A037338 Adjacent sequences:  A279623 A279624 A279625 * A279627 A279628 A279629 KEYWORD nonn AUTHOR Jeffrey Shallit, Dec 16 2016 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.

Last modified September 27 08:39 EDT 2021. Contains 347689 sequences. (Running on oeis4.)