A090280 "Plain Bob Minimus" in bell-ringing is a sequence of permutations p_1=(1,2,3,4), p_2=(2,1,4,3), .. which runs through all permutations of {1,2,3,4} with period 24; sequence gives number in position 4 of n-th permutation.

4, 3, 3, 1, 1, 2, 2, 4, 2, 4, 4, 1, 1, 3, 3, 2, 3, 2, 2, 1, 1, 4, 4, 3, 4, 3, 3, 1, 1, 2, 2, 4, 2, 4, 4, 1, 1, 3, 3, 2, 3, 2, 2, 1, 1, 4, 4, 3, 4, 3, 3, 1, 1, 2, 2, 4, 2, 4, 4, 1, 1, 3, 3, 2, 3, 2, 2, 1, 1, 4, 4, 3, 4, 3, 3, 1, 1, 2, 2, 4, 2, 4, 4, 1, 1, 3, 3, 2, 3, 2, 2, 1, 1, 4, 4, 3, 4, 3, 3

Offset

1,1

Links

Table of n, a(n) for n=1..99.

R. Bailey, Change Ringing Resources

David Joyner, Application: Bell Ringing

Index entries for linear recurrences with constant coefficients, signature (1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1, -1, 1).

Index entries for sequences related to bell ringing

Formula

Period 24.

From Chai Wah Wu, Jul 17 2016: (Start)

a(n) = a(n-1) - a(n-2) + a(n-3) - a(n-4) + a(n-5) - a(n-6) + a(n-7) - a(n-8) + a(n-9) - a(n-10) + a(n-11) - a(n-12) + a(n-13) - a(n-14) + a(n-15) - a(n-16) + a(n-17) - a(n-18) + a(n-19) - a(n-20) + a(n-21) - a(n-22) + a(n-23) for n > 23.

G.f.: x*(-3*x^22 - x^21 - 3*x^20 + 2*x^19 - 3*x^18 + x^17 - 3*x^16 - 2*x^14 - x^13 - 2*x^12 + x^11 - 2*x^10 - 2*x^9 - 2*x^8 - 4*x^6 + 2*x^5 - 4*x^4 + 3*x^3 - 4*x^2 + x - 4)/((x - 1)*(x^2 + 1)*(x^4 + 1)*(x^2 - x + 1)*(x^2 + x + 1)*(x^4 - x^2 + 1)*(x^8 - x^4 + 1)). (End)

Maple

ring:= proc(k) option remember; local l, a, b, c, swap, h; l:= [1, 2, 3, 4]; swap:= proc(i, j) h:=l[i]; l[i]:=l[j]; l[j]:=h end; a:= proc() swap(1, 2); swap(3, 4); l[k] end; b:= proc() swap(2, 3); l[k] end; c:= proc() swap(3, 4); l[k] end; [l[k], seq([seq([a(), b()][], j=1..3), a(), c()][], i=1..3)] end: a:= n-> ring(4)[modp(n-1, 24)+1]: seq(a(n), n=1..99); # Alois P. Heinz, Aug 19 2008

Mathematica

ring[k_] := ring[k] = Module[{l, a, b, c, swap, h}, l = Range[4]; swap[i_, j_] := (h = l[[i]]; l[[i]] = l[[j]]; l[[j]] = h); a := (swap[1, 2]; swap[3, 4]; l[[k]]); b := (swap[2, 3]; l[[k]]); c := (swap[3, 4]; l[[k]] ); Join[{l[[k]]}, Flatten @ Table[ Join[ Flatten @ Table[{a, b}, {j, 1, 3}], {a}, {c}], {i, 1, 3}]]] ; a[n_] := ring[4][[Mod[n-1, 24] + 1]]; Table[a[n], {n, 1, 99}] (* Jean-François Alcover, Mar 18 2017, after Alois P. Heinz *)

Crossrefs

Cf. A090277-A090284.

Sequence in context: A200617 A016699 A060373 * A177158 A177034 A177933

Adjacent sequences: A090277 A090278 A090279 * A090281 A090282 A090283

Keyword

nonn

Author

N. J. A. Sloane, Jan 24 2004

Status

approved