The OEIS is supported by the many generous donors to the OEIS Foundation. Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A336749 Number of circular arrangements of the first n positive integers such that adjacent terms have absolute difference 1 or 4. 0
 1, 0, 1, 1, 1, 3, 2, 3, 6, 5, 10, 12, 14, 25, 27, 40, 57, 68, 104, 133, 177, 255, 324, 454, 617, 811, 1136, 1507, 2042, 2803, 3729, 5109, 6904, 9290, 12692, 17070, 23152, 31430, 42361, 57567, 77842, 105279, 142865, 193040, 261589, 354316, 479189, 649498, 878905 (list; graph; refs; listen; history; text; internal format)
 OFFSET 5,6 COMMENTS Permutations in which adjacent terms sum to a particular value is a property central to the sequences A090460, A071984, A108658, A272259, and A107929. LINKS Ethan P. White, Richard K. Guy, Renate Scheidler, Difference Necklaces, arXiv:2006.15250 [math.CO], 2020. See Table A.1 p. 31. Index entries for linear recurrences with constant coefficients, signature (-1,0,1,1,2,2,1,1,1). FORMULA a(n) = -a(n-1) + a(n-3) + a(n-4) + 2*a(n-5) + 2*a(n-6) + a(n-7) + a(n-8) + a(n-9) for n > 13. G.f.: x^5*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)/(1 + x - x^3 - x^4 - 2*x^5 - 2*x^6 - x^7 - x^8 - x^9). - Stefano Spezia, Aug 03 2020 MATHEMATICA CoefficientList[ Series[(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)/(1 + x - x^3 - x^4 - 2*x^5 - 2*x^6 - x^7 - x^8 - x^9), {x, 0, 50}], x] (* Wesley Ivan Hurt, Nov 07 2020 *) CROSSREFS See A079977 or A017899 for other sequences counting similar circular arrangements of positive integers. Sequence in context: A033807 A058691 A281667 * A214297 A022472 A014679 Adjacent sequences:  A336746 A336747 A336748 * A336750 A336751 A336752 KEYWORD nonn,easy AUTHOR Ethan Patrick White, Aug 02 2020 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 August 14 05:20 EDT 2022. Contains 356110 sequences. (Running on oeis4.)