A001883
Number of permutations s of {1,2,...,n} such that |s(i)-i|>1 for each i=1,2,...,n.
Original entry on oeis.org
1, 0, 0, 0, 1, 4, 29, 206, 1708, 15702, 159737, 1780696, 21599745, 283294740, 3995630216, 60312696452, 970234088153, 16571597074140, 299518677455165, 5711583170669554, 114601867572247060, 2413623459384988298, 53238503492701261201, 1227382998752177970288, 29520591675204638641249
Offset: 0
- J. Riordan, "The enumeration of permutations with three-ply staircase restrictions," unpublished memorandum, Bell Telephone Laboratories, Murray Hill, NJ, Oct 1963.
- N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
- Eric M. Schmidt, Table of n, a(n) for n = 0..200
- Dmitry Efimov, Determinants of generalized binary band matrices, arXiv:1702.05655 [math.RA], 2017.
- J. Riordan, Letter, Oct 31 1977
- N. J. A. Sloane, Annotated copy of Riordan's Three-Ply Staircase paper
- Donovan Young, The Number of Domino Matchings in the Game of Memory, J. Int. Seq., Vol. 21 (2018), Article 18.8.1.
- Donovan Young, Generating Functions for Domino Matchings in the 2 X k Game of Memory, J. Int. Seq., Vol. 22 (2019), Article 19.8.7.
- D. Zeilberger, Automatic Enumeration of Generalized Menage Numbers, arXiv preprint arXiv:1401.1089 [math.CO], 2014.
-
b:= proc(n, s) option remember; `if`(n=0, 1, add(
`if`(abs(n-i)<=1, 0, b(n-1, s minus {i})), i=s))
end:
a:= n-> b(n, {$1..n}):
seq(a(n), n=0..15); # Alois P. Heinz, Jul 04 2015
-
b[n_, s_List] := b[n, s] = If[n == 0, 1, Sum[If[Abs[n-i] <= 1, 0, b[n-1, s ~Complement~ {i}]], {i, s}]]; a[n_] := b[n, Range[n]]; Table[Print[a[n]]; a[n], {n, 4, 24}] (* Jean-François Alcover, Nov 10 2015, after Alois P. Heinz *)
-
permRWNb(a)=n=matsize(a)[1]; if(n==1,return(a[1,1])); sg=1; in=vectorv(n); x=in; x=a[,n]-sum(j=1,n,a[,j])/2; p=prod(i=1,n,x[i]); for(k=1,2^(n-1)-1,sg=-sg; j=valuation(k,2)+1; z=1-2*in[j]; in[j]+=z; x+=z*a[,j]; p+=prod(i=1,n,x[i],sg)); return(2*(2*(n%2)-1)*p)
for(n=1,23,a=matrix(n,n,i,j,abs(i-j)>1);print1(permRWNb(a)",")) \\ Herman Jamke (hermanjamke(AT)fastmail.fm), May 16 2007
More terms and better description from
Reiner Martin, Oct 14 2002
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 16 2007
A058057
Triangle giving coefficients of ménage hit polynomials.
Original entry on oeis.org
1, 1, 0, 1, 1, 0, 1, 3, 1, 1, 1, 6, 6, 8, 3, 1, 10, 20, 38, 35, 16, 1, 15, 50, 134, 213, 211, 96, 1, 21, 105, 385, 915, 1479, 1459, 675, 1, 28, 196, 952, 3130, 7324, 11692, 11584, 5413, 1, 36, 336, 2100, 9090, 28764, 65784, 104364, 103605, 48800
Offset: 0
1; 1,0; 1,1,0; 1,3,1,1; 1,6,6,8,3; ...
- J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 198.
-
V := proc(n) local k; add( binomial(2*n-k,k)*(n-k)!*(x-1)^k, k=0..n); end; W := proc(r,s) coeff( V(r),x,s ); end; a := (n,k)->W(n,n-k);
-
max = 9; f[x_, y_] := Sum[n!*((x*y)^n/(1 + x*(y-1))^(2*n+1)), {n, 0, max}]; Flatten[ MapIndexed[ Take[#1, #2[[1]]] & , CoefficientList[ Series[f[x, y], {x, 0, max}, {y, 0, max}], {x, y}]]] (*Jean-François Alcover, Jun 29 2012, after Vladeta Jovovic *)
A080061
Triangle of coefficients of polynomials P(n; x) = Permanent(M), where M=[m(i,j)] is n X n matrix defined by m(i,j)=x if 0<=i-j<=2 else m(i,j)=1.
Original entry on oeis.org
1, 0, 1, 0, 1, 1, 0, 1, 4, 1, 1, 4, 8, 10, 1, 5, 21, 38, 34, 21, 1, 33, 122, 209, 206, 109, 40, 1, 236, 849, 1400, 1351, 836, 295, 72, 1, 1918, 6719, 10849, 10543, 6629, 2821, 715, 125, 1, 17440, 59873, 95516, 92708, 60284, 26870, 8372, 1604, 212, 1, 175649, 593686
Offset: 0
1;
0,1;
0,1,1;
0,1,4,1;
1,4,8,10,1;
5,21,38,34,21,1;
... P(5; x) = Permanent(Matrix(5, 5, [[x,1,1,1,1],[x,x,1,1,1],[x,x,x,1,1],[1,x,x,x,1],[1,1,x,x,x]]))= 5+21*x+38*x^2+34*x^3+21*x^4+x^5.
- J. Riordan, The enumeration of permutations with three-ply staircase restrictions, unpublished memorandum, Bell Telephone Laboratories, Murray Hill, NJ, Oct 1963. See Table 1. - N. J. A. Sloane, Aug 27 2013 (See A001883)
-
A080061_line := proc(n)
local M,r,c,p,pord ;
if n = 0 then
return [1] ;
else
M := Matrix(n,n) ;
for r to n do
for c to n do
if r-c >=0 and r-c <=2 then
M[r,c] := x ;
else
M[r,c] := 1 ;
end if;
end do:
end do:
p := LinearAlgebra[Permanent](M) ;
pord := degree(p) ;
[seq( coeff(p,x,r),r=0..pord)] ;
end if;
end proc:
for n from 0 to 10 do
print(A080061_line(n)) ;
end do: # R. J. Mathar, Sep 18 2013
-
M[n_] := Table[If[0 <= i-j <= 2, x, 1], {i, 1, n}, {j, 1, n}]; M[0]={{1}}; Table[CoefficientList[Permanent[M[n]], x], {n, 0, 10}] // Flatten (* Jean-François Alcover, Jan 06 2016 *)
A001884
Hit polynomials.
Original entry on oeis.org
1, 0, 1, 2, 20, 104, 775, 6140, 55427, 553802, 6087992, 72994152, 948103477, 13262133736, 198769630061, 3177862894922, 53984653965996, 971068821144112, 18438722595913195, 368558842844143268, 7735520783692157215, 170095060428041137778, 3910332719957508452016, 93806427360751009531632
Offset: 1
- J. Riordan, The enumeration of permutations with three-ply staircase restrictions, unpublished memorandum, Bell Telephone Laboratories, Murray Hill, NJ, Oct 1963. See A001883.
- N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
A001885
Hit polynomials.
Original entry on oeis.org
2, 2, 10, 28, 207, 1288, 10366, 91296, 903037, 9832848, 117032570, 1510932116, 21028774738, 313832463386, 4999133311044, 84655108256252, 1518546437350265, 28763765236019284, 573689119174695326, 12017485839703597024, 263787711208968183879, 6054632852404055079936
Offset: 2
- J. Riordan, The enumeration of permutations with three-ply staircase restrictions, unpublished memorandum, Bell Telephone Laboratories, Murray Hill, NJ, Oct 1963. (See A001883).
- N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
A001886
Hit polynomials.
Original entry on oeis.org
3, 6, 44, 180, 1407, 10384, 92896, 911512, 9913152, 117788056, 1519021046, 21123287848, 315034832581, 5015656588706, 84899016219708, 1522394744470356, 28828385427350245, 574839634258405032, 12039133083940334978, 264216869431056251276, 6063573884814663905952
Offset: 3
- J. Riordan, The enumeration of permutations with three-ply staircase restrictions, unpublished memorandum, Bell Telephone Laboratories, Murray Hill, NJ, Oct 1963. (See A001883)
- N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
Showing 1-6 of 6 results.
Comments