The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A285485 Number of (n+1)-extended Skolem sequences of order n. 0
 0, 0, 2, 2, 0, 0, 44, 260, 0, 0, 33104, 203712, 0, 0, 75499696, 621309008, 0, 0, 492805156768, 5068810602400, 0, 0, 7346944632542720 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Number of Rosa sequences of order n. a(n) computed counting reflected solutions. LINKS Table of n, a(n) for n=1..23. N. Francetić, E. Mendelsohn, A survey of Skolem-type sequences and Rosa's use of them, Math. Slovaca 59 (2009), pp. 39-76 Jeppe Winther Larsen, Counting the Skolem sequences using inclusion-exclusion R. Rees, N. Shalaby, A. Sharary, Indecomposable Skolem and Rosa sequences EXAMPLE For n = 3, there are 2 solutions: 1 1 3 0 2 3 2 and 2 3 2 0 3 1 1. For n = 4, there are 2 solutions: 1 1 3 4 0 3 2 4 2 and 2 4 2 3 0 4 3 1 1. CROSSREFS Cf. A004077, A004075 Sequence in context: A282441 A281988 A190389 * A176127 A087637 A052458 Adjacent sequences: A285482 A285483 A285484 * A285486 A285487 A285488 KEYWORD nonn,more AUTHOR Fausto A. C. Cariboni, Apr 19 2017 EXTENSIONS a(1)-a(18) from Jeppe Winther Larsen (jwl(AT)itu.dk), Oct 12 2009 a(1)-a(18) confirmed, a(19)-a(22) from Fausto A. C. Cariboni, Apr 19 2017 a(23) from Fausto A. C. Cariboni, May 11 2017 STATUS approved

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

Last modified September 11 13:11 EDT 2024. Contains 375829 sequences. (Running on oeis4.)