OFFSET
0,2
COMMENTS
Number of moves to solve Type 4 Zig-Zag puzzle.
REFERENCES
Richard I. Hess, Compendium of Over 7000 Wire Puzzles, privately printed, 1991.
Richard I. Hess, Analysis of Ring Puzzles, booklet distributed at 13th International Puzzle Party, Amsterdam, Aug 20 1993.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = 2*a(n-1)+3*a(n-2)+5, a(0)=1; a(1)=1. - Zerinvary Lajos, Dec 14 2008
a(n) = (3^(n+3) - 19^((n+1) mod 2))/8. - Wesley Ivan Hurt, Nov 13 2013
MAPLE
f:=n->if n mod 2 = 0 then (3^(n+3)-19)/8 else (3^(n+3)-1)/8; fi;
a[0]:=1:a[1]:=1:for n from 2 to 50 do a[n]:=2*a[n-1]+3*a[n-2]+5 od: seq(a[n], n=1..33); # Zerinvary Lajos, Dec 14 2008
MATHEMATICA
f[n_]:=Module[{c=3^(n+3)}, If[EvenQ[n], (c-19)/8, (c-1)/8]]; Array[f, 30, 0] (* Harvey P. Dale, Oct 23 2012 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Apr 01 2006
STATUS
approved