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.

Showing 1-10 of 11 results. Next

A102098 Triangular matrix, read by rows, that satisfies: T(n,k) = [T^3](n-1,k) when n>k>=0, with T(n,n) = (n+1).

Original entry on oeis.org

1, 1, 2, 7, 8, 3, 139, 152, 27, 4, 5711, 6200, 999, 64, 5, 408354, 442552, 69687, 3904, 125, 6, 45605881, 49399320, 7724835, 416704, 11375, 216, 7, 7390305396, 8003532512, 1248465852, 66464960, 1725875, 27432, 343, 8, 1647470410551
Offset: 0

Views

Author

Paul D. Hanna, Dec 29 2004

Keywords

Comments

Column 0 forms A082162. Column 1 forms A102099. Row sums form A102100. This triangle is a variant of A102086.

Examples

			Rows of T begin:
[1],
[1,2],
[7,8,3],
[139,152,27,4],
[5711,6200,999,64,5],
[408354,442552,69687,3904,125,6],
[45605881,49399320,7724835,416704,11375,216,7],
[7390305396,8003532512,1248465852,66464960,1725875,27432,343,8],...
Matrix cube T^3 equals T excluding the main diagonal:
[1],
[7,8],
[139,152,27],
[5711,6200,999,64],
[408354,442552,69687,3904,125],...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=local(A=matrix(1,1),B);A[1,1]=1; for(m=2,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=j,if(j==1,B[i,j]=(A^3)[i-1,1], B[i,j]=(A^3)[i-1,j]));));A=B);return(A[n+1,k+1])}

Formula

T(n, 0) = A082162(n) for n>0, with T(0, 0) = 1.

A082170 Deterministic completely defined quasi-acyclic automata with 3 inputs, n transient and k absorbing labeled states.

Original entry on oeis.org

1, 1, 1, 1, 8, 15, 1, 27, 368, 1024, 1, 64, 2727, 53672, 198581, 1, 125, 11904, 710532, 18417792, 85102056, 1, 216, 38375, 4975936, 386023509, 12448430408, 68999174203, 1, 343, 101520, 23945000, 3977848832, 381535651512, 14734002979456, 95264160938080
Offset: 0

Views

Author

Valery A. Liskovets, Apr 09 2003

Keywords

Comments

Array read by antidiagonals: (0,1),(0,2),(1,1),(0,3),...
The first column is A082158.

Examples

			The array begins:
            1,              1,               1,             1, ...;
            1,              8,              27,            64, ...;
           15,            368,            2727,         11904, ...;
         1024,          53672,          710532,       4975936, ...;
       198581,       18417792,       386023509,    3977848832, ...;
     85102056,    12448430408,    381535651512, 5451751738944, ...;
  68999174203, 14734002979456, 624245820664563, ...;
Antidiagonals begin as:
  1;
  1,   1;
  1,   8,    15;
  1,  27,   368,    1024;
  1,  64,  2727,   53672,    198581;
  1, 125, 11904,  710532,  18417792,    85102056;
  1, 216, 38375, 4975936, 386023509, 12448430408, 68999174203;
		

Crossrefs

Programs

  • Magma
    function A(n,k)
      if n eq 0 then return 1;
      else return (&+[(-1)^(n-j+1)*Binomial(n,j)*(k+j)^(3*n-3*j)*A(j,k): j in [0..n-1]]);
      end if;
    end function;
    A082170:= func< n,k | A(k,n-k+1) >;
    [A082170(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jan 19 2024
    
  • Mathematica
    T[0, ] = 1; T[n, k_]:= T[n, k] = Sum[Binomial[n, i] (-1)^(n-i-1)*(i + k)^(3n-3i) T[i, k], {i,0,n-1}];
    Table[T[n-k-1, k], {n, 1, 9}, {k, n-1, 1, -1}]//Flatten (* Jean-François Alcover, Aug 29 2019 *)
  • SageMath
    @CachedFunction
    def A(n,k):
        if n==0: return 1
        else: return sum((-1)^(n-j+1)*binomial(n,j)*(k+j)^(3*n-3*j)*A(j,k) for j in range(n))
    def A082170(n,k): return A(k,n-k+1)
    flatten([[A082170(n,k) for k in range(n+1)] for n in range(12)]) # G. C. Greubel, Jan 19 2024

Formula

T(n, k) = T_3(n, k) where T_3(0, k) = 1, T_3(n, k) = Sum_{i=0..n-1} (-1)^(n-i-1)*binomial(n, i)*(i+k)^(3*n-3*i)*T_3(i, k), n > 0.

A102916 Triangle, read by rows, where the antidiagonals are formed by interleaving the rows of triangle A102098 with the rows of its matrix square (A102920).

Original entry on oeis.org

1, 1, 2, 1, 4, 3, 3, 8, 9, 4, 7, 40, 27, 16, 5, 36, 152, 189, 64, 25, 6, 139, 1128, 999, 576, 125, 36, 7, 1036, 6200, 9720, 3904, 1375, 216, 49, 8, 5711, 61120, 69687, 47040, 11375, 2808, 343, 64, 9, 56355, 442552, 857466, 416704, 163500, 27432, 5145, 512
Offset: 0

Views

Author

Paul D. Hanna, Jan 21 2005

Keywords

Comments

Column 0 is A102917, the interleaving of A082162 with A102921. Under matrix cube, triangle A102098 shifts each column up 1 row.

Examples

			Rows begin:
[1],
[1,2],
[1,4,3],
[3,8,9,4],
[7,40,27,16,5],
[36,152,189,64,25,6],
[139,1128,999,576,125,36,7],
[1036,6200,9720,3904,1375,216,49,8],
[5711,61120,69687,47040,11375,2808,343,64,9],...
The antidiagonals are formed by interleaving the
rows of triangle A102098:
[1],
[1,2],
[7,8,3],
[139,152,27,4],...
with the rows of the matrix square of A102098,
which is triangle A102920:
[1],
[3,4],
[36,40,9],
[1036,1128,189,16],...
G.f. for Column 0 (A102917): 1 = 1*(1-x) + 1*x*(1-x)
+ 1*x^2*(1-x)(1-2x) + 3*x^3*(1-x)(1-2x)
+ 7*x^4*(1-x)(1-2x)(1-3x) + 36*x^5*(1-x)(1-2x)(1-3x) +...
+ A082162(n)*x^(2n)*(1-x)(1-2x)*..*(1-(n+1)x)
+ A102921(n)*x^(2n+1)*(1-x)(1-2x)*..*(1-(n+1)x) + ...
G.f. for Column 1 (A102918): 2 = 2*(1-2x) + 4*x*(1-2x)
+ 8*x^2*(1-2x)(1-3x) + 40*x^3*(1-2x)(1-3x)
+ 152*x^4*(1-2x)(1-3x)(1-4x) + 1128*x^5*(1-2x)(1-3x)(1-4x) +...
+ T(2n+1,1)*x^(2n)*(1-2x)(1-3x)*..*(1-(n+2)x)
+ T(2n+2,1)*x^(2n+1)*(1-2x)(1-3x)*..*(1-(n+2)x) + ...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=if(n
    				

Formula

G.f. for column k: T(k, k) = k+1 = Sum_{n>=0} T(n+k, k)*x^n*Product_{j=k..[n/2+k]} (1-(j+1)*x).

A102099 Column 1 of triangular matrix A102098, which shifts upward to exclude the main diagonal under matrix cube.

Original entry on oeis.org

0, 2, 8, 152, 6200, 442552, 49399320, 8003532512, 1784040237288, 525504809786112, 198213959637435608, 93352856625931514024, 53776417402985961020144, 37244016639064540041311632
Offset: 0

Views

Author

Paul D. Hanna, Dec 29 2004

Keywords

Comments

Column 0 of A102098 is A082162.

Crossrefs

Programs

  • PARI
    {a(n)=local(A=matrix(2,2),B);A[1,1]=1; for(m=2,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=j,if(j==1,B[i,j]=(A^3)[i-1,1], B[i,j]=(A^3)[i-1,j]));));A=B); return(A[n+1,2])}

A102101 Triangular matrix, read by rows, that satisfies: T(n,k) = [T^4](n-1,k) when n>k>=0, with T(n,n) = (n+1).

Original entry on oeis.org

1, 1, 2, 15, 16, 3, 1000, 1040, 81, 4, 189035, 196080, 14175, 256, 5, 79278446, 82196224, 5866992, 94464, 625, 6, 63263422646, 65585046960, 4667640795, 73281280, 419375, 1296, 7, 86493299281972, 89664824687968, 6376139907030
Offset: 0

Views

Author

Paul D. Hanna, Dec 29 2004

Keywords

Comments

Column 0 forms A102102. Column 1 forms A102103. Row sums form A102104. This triangle is a variant of A102086 and A102098.

Examples

			Rows of T begin:
[1],
[1,2],
[15,16,3],
[1000,1040,81,4],
[189035,196080,14175,256,5],
[79278446,82196224,5866992,94464,625,6],
[63263422646,65585046960,4667640795,73281280,419375,1296,7].
Matrix fourth power T^4 equals T excluding the main diagonal:
[1],
[15,16],
[1000,1040,81],
[189035,196080,14175,256],
[79278446,82196224,5866992,94464,625],...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=local(A=matrix(1,1),B);A[1,1]=1; for(m=2,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=j,if(j==1,B[i,j]=(A^4)[i-1,1], B[i,j]=(A^4)[i-1,j]));));A=B);return(A[n+1,k+1])}

Formula

T(n, 0) = A082162(n) for n>0, with T(0, 0) = 1.

A102917 Column 0 of triangle A102916.

Original entry on oeis.org

1, 1, 1, 3, 7, 36, 139, 1036, 5711, 56355, 408354, 5045370, 45605881, 679409158, 7390305396, 129195427716, 1647470410551, 33114233390505, 485292763088275, 11038606786054201, 183049273155939442, 4652371578279864792
Offset: 0

Views

Author

Paul D. Hanna, Jan 21 2005

Keywords

Comments

Also equals the interleaving of A082162 with A102921, which equal column 0 of triangle A102098 and its matrix square (A102920), respectively.

Examples

			1 = 1*(1-x) + 1*x*(1-x) + 1*x^2*(1-x)(1-2x) + 3*x^3*(1-x)(1-2x)
+ 7*x^4*(1-x)(1-2x)(1-3x) + 36*x^5*(1-x)(1-2x)(1-3x)
+ 139*x^6*(1-x)(1-2x)(1-3x)(1-4x) + 1036*x^7*(1-x)(1-2x)(1-3x)(1-4x) + ...
+ A082162(n)*x^(2n)*(1-x)(1-2x)*..*(1-(n+1)x)
+ A102921(n)*x^(2n+1)*(1-x)(1-2x)*..*(1-(n+1)x) + ...
		

Crossrefs

Programs

  • PARI
    {a(n)=if(n==0,1,polcoeff(1-sum(k=0,n-1,a(k)*x^k*prod(j=1,k\2+1,1-j*x+x*O(x^n))),n))}

Formula

G.f.: 1 = Sum_{n>=0}(a(2*n)+a(2*n+1)*x)*x^(2*n)*Product_{k=1..n+1}(1-k*x) where a(2*n)=A082162(n) and a(2*n+1)=A102921(n).

A082164 Deterministic completely defined initially connected acyclic automata with 3 inputs and n+1 transient unlabeled states including a unique state having all transitions to the absorbing state.

Original entry on oeis.org

1, 7, 133, 5362, 380093, 42258384, 6830081860, 1520132414241, 447309239576913, 168599289097947589, 79364534944804317166, 45701029702436877135199, 31642128418550547009710906, 25960688434777959685891570936, 24926392120419324125117256758595, 27708074645788511889179577045508824
Offset: 1

Views

Author

Valery A. Liskovets, Apr 09 2003

Keywords

Comments

Coefficients T_2(n,k) form the array A082172. These automata have no nontrivial automorphisms (by states).

Crossrefs

Programs

  • Mathematica
    b[, 0, ] = 1; b[k_, n_, r_] := b[k, n, r] = Sum[Binomial[n, t] (-1)^(n - t - 1) ((t + r + 1)^k - 1)^(n - t) b[k, t, r], {t, 0, n - 1}];
    d3[n_] := d3[n] = b[3, n, 1] - Sum[Binomial[n - 1, j - 1] T3[n - j, j + 1] d3[j], {j, 1, n - 1}];
    T3[0, ] = 1; T3[n, k_] := T3[n, k] = Sum[Binomial[n, i] (-1)^(n - i - 1) ((i + k + 1)^3 - 1)^(n - i) T3[i, k], {i, 0, n - 1}];
    a[n_] := If[n == 1, 1, d3[n - 1]/(n - 2)!];
    Array[a, 20] (* Jean-François Alcover, Aug 29 2019 *)

Formula

a(n) := d_3(n)/(n-1)! where d_3(n) := b_3(n, 1)-sum(binomial(n-1, j-1)*T_3(n-j, j+1)*d_3(j), j=1..n-1); and T_3(0, k) := 1, T_3(n, k) := sum(binomial(n, i)*(-1)^(n-i-1)*((i+k+1)^3-1)^(n-i)*T_3(i, k), i=0..n-1), n>0.

Extensions

More terms from Jean-François Alcover, Aug 29 2019

A102102 Column 0 of triangular matrix A102101, which shifts upward to exclude the main diagonal under matrix fourth power.

Original entry on oeis.org

1, 1, 15, 1000, 189035, 79278446, 63263422646, 86493299281972, 187766975052827491, 611024291011881918991, 2849262494779035461688236, 18362167739517547774072439880, 158759599858376078627687256207242
Offset: 0

Views

Author

Paul D. Hanna, Dec 29 2004

Keywords

Comments

Analogous to A082161 and A082162, this describes the deterministic completely defined initially connected acyclic automata with 4 inputs and n transient unlabeled states (and a unique absorbing state) with a(0)=1.

Crossrefs

Programs

  • PARI
    {a(n)=local(A=matrix(1,1),B);A[1,1]=1; for(m=2,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=j,if(j==1,B[i,j]=(A^4)[i-1,1], B[i,j]=(A^4)[i-1,j]));));A=B);return(A[n+1,1])}

A102400 Triangle, read by rows, where T(n,k) = Sum_{j=0..k} T(n-1,j)*(j+1)*[(k+1)*(k+2)/2 - j*(j+1)/2] for n>k>0, with T(0,0)=1 and T(n,n) = T(n,n-1) for n>0.

Original entry on oeis.org

1, 1, 1, 1, 7, 7, 1, 31, 139, 139, 1, 127, 1567, 5711, 5711, 1, 511, 15379, 126579, 408354, 408354, 1, 2047, 143527, 2357431, 15333661, 45605881, 45605881, 1, 8191, 1312219, 40769819, 473433344, 2634441290, 7390305396, 7390305396, 1, 32767
Offset: 0

Views

Author

Paul D. Hanna, Jan 06 2005

Keywords

Comments

Main diagonal is A082162 (with offset). This sequence is derived from column 0 of A102098.

Examples

			T(4,2) = 1567 = 1*6 + 31*10 + 139*9
= T(3,0)*R(0,2) + T(3,1)*R(1,2) + T(3,2)*R(2,2).
Rows begin:
[1],
[1,1],
[1,7,7],
[1,31,139,139],
[1,127,1567,5711,5711],
[1,511,15379,126579,408354,408354],
[1,2047,143527,2357431,15333661,45605881,45605881],...
where the transpose of the recurrence coefficients given by
[R^t](n,k) = (k+1)*((n+1)*(n+2)/2 - k*(k+1)/2) form triangle:
[1],
[3,4],
[6,10,9],
[10,18,21,16],
[15,28,36,36,25],...
which equals the matrix square of the triangle:
[1],
[1,2],
[1,2,3],
[1,2,3,4],
[1,2,3,4,5],...
		

Crossrefs

Programs

  • Mathematica
    T[n_, k_] := T[n, k] = If[nJean-François Alcover, Dec 15 2014, after PARI *)
  • PARI
    {T(n,k)=if(n
    				

A103241 Unreduced numerators of the elements T(n,k)/(n-k)!, read by rows, of the triangular matrix P^-1, which is the inverse of the matrix defined by P(n,k) = (-k^3)^(n-k)/(n-k)! for n >= k >= 1.

Original entry on oeis.org

1, 1, 1, 15, 8, 1, 1024, 368, 27, 1, 198581, 53672, 2727, 64, 1, 85102056, 18417792, 710532, 11904, 125, 1, 68999174203, 12448430408, 386023509, 4975936, 38375, 216, 1, 95264160938080, 14734002979456, 381535651512, 3977848832, 23945000
Offset: 1

Views

Author

Paul D. Hanna, Feb 02 2005

Keywords

Comments

Define a triangular matrix P where P(n,k) = (-k^3)^(n-k)/(n-k)!, then M = P*D*P^-1 = A102098 satisfies M^3 = SHIFTUP(M) where D is the diagonal matrix consisting of {1,2,3,...}. The operation SHIFTUP(M) shifts each column of M up 1 row.
Essentially equal to square array A082170 as a triangular matrix. The first column is A082162 (enumerates acyclic automata with 3 inputs).

Examples

			Rows of unreduced fractions T(n,k)/(n-k)! begin:
  [1/0!],
  [1/1!, 1/0!],
  [15/2!, 8/1!, 1/0!],
  [1024/3!, 368/2!, 27/1!, 1/0!],
  [198581/4!, 53672/3!, 2727/2!, 64/1!, 1/0!],
  [85102056/5!, 18417792/4!, 710532/3!, 11904/2!, 125/1!, 1/0!], ...
forming the inverse of matrix P where P(n,k) = A103246(n,k)/(n-k)!:
  [1/0!],
  [-1/1!, 1/0!],
  [1/2!, -8/1!, 1/0!],
  [-1/3!, 64/2!, -27/1!, 1/0!],
  [1/4!, -512/3!, 729/2!, -64/1!, 1/0!], ...
		

Crossrefs

Programs

  • PARI
    {T(n,k)=my(P);if(n>=k&k>=1, P=matrix(n,n,r,c,if(r>=c,(-c^3)^(r-c)/(r-c)!))); return(if(n
    				

Formula

For n > k >= 1: 0 = Sum_{m=k..n} C(n-k, m-k)*(-m^3)^(n-m)*T(m, k).
For n > k >= 1: 0 = Sum_{j=k..n} C(n-k, j-k)*(-k^3)^(j-k)*T(n, j).
Showing 1-10 of 11 results. Next