cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A003170 Number of 4 X n Latin rectangles in which the first row is in order.

Original entry on oeis.org

24, 1344, 393120, 155185920, 88390995840, 69761852246016, 74175958614030336, 103657593656495554560, 186355188348102566876160, 423073240119513285788344320, 1193404222275011001999025311744, 4123706289611916312851104783171584, 17237448791456599571078045378751528960
Offset: 4

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References

  • S. M. Kerawala, The enumeration of the Latin rectangle of depth three by means of a difference equation, Bull. Calcutta Math. Soc., 33 (1941), 119-127.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Equals A000573*(n-1)!/(n-4)!.

Programs

  • GAP
    ChooseList:=function(a,B) local x,p,i; x:=a; p:=1; for i in B do p:=p*Binomial(x,i); x:=x-i; od; return p; end;;
    DoylePartitions:=function(n) return Union(List(Partitions(n+8,8)-1,P->PermutationsList(P))); end;;
    DoyleF1:=function(A) return A[1]+A[3]+A[2]+A[4]; end;;
    DoyleF2:=function(A) return A[1]+A[2]+A[5]+A[6]; end;;
    DoyleF3:=function(A) return A[1]+A[3]+A[5]+A[7]; end;;
    DoyleF12:=function(A) return A[1]+A[2]; end;;
    DoyleF23:=function(A) return A[1]+A[5]; end;;
    DoyleF13:=function(A) return A[1]+A[3]; end;;
    DoyleF123:=function(A) return A[1]; end;;
    DoyleG:=function(A) return DoyleF1(A)*DoyleF2(A)*DoyleF3(A) -DoyleF12(A)*DoyleF3(A) -DoyleF23(A)*DoyleF1(A) -DoyleF13(A)*DoyleF2(A) +2*DoyleF123(A); end;;
    DoyleGProduct:=function(A) local i,p,B; p:=1; for i in [1..8] do B:=List(A,j->j); B[i]:=B[i]-1; B[8]:=B[8]+1; p:=p*DoyleG(B)^A[i]; od; return p; end;;
    NrFourLineNormalisedLatinRectanglesDoyle:=function(n) local count,A; count:=0; for A in DoylePartitions(n) do count:=count+(-1)^(A[2]+A[3]+A[5]+2*(A[4]+A[6]+A[7])+3*A[8])*ChooseList(n,A)*DoyleGProduct(A); od; return count; end;; # Douglas Stones (douglas.stones(AT)sci.monash.edu.au), Apr 01 2009, Sep 05 2009

Extensions

Doron Zeilberger pointed out that was an error in a(10), which has now been corrected.
More terms from Douglas Stones (douglas.stones(AT)sci.monash.edu.au), Apr 01 2009