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 1-4 of 4 results.

A111840 Triangle P, read by rows, that satisfies [P^3](n,k) = P(n+1,k+1) for n>=k>=0, also [P^(3*m)](n,k) = [P^m](n+1,k+1) for all m, where [P^m](n,k) denotes the element at row n, column k, of the matrix power m of P, with P(k,k)=1 and P(k+1,1)=P(k+1,0) for k>=0.

Original entry on oeis.org

1, 1, 1, 3, 3, 1, 18, 18, 9, 1, 216, 216, 135, 27, 1, 5589, 5589, 4050, 1134, 81, 1, 336555, 336555, 269730, 95256, 9963, 243, 1, 49768101, 49768101, 42724503, 17926839, 2450898, 88938, 729, 1, 18707873562, 18707873562, 16835895603, 8074043145
Offset: 0

Views

Author

Paul D. Hanna, Aug 22 2005

Keywords

Comments

Column 0 and column 1 are equal for n>0.

Examples

			Let q=3; the g.f. of column k of matrix power P^m is:
1 + (m*q^k)*L(x) + (m*q^k)^2/2!*L(x)*L(q*x) +
(m*q^k)^3/3!*L(x)*L(q*x)*L(q^2*x) +
(m*q^k)^4/4!*L(x)*L(q*x)*L(q^2*x)*L(q^3*x) + ...
where L(x) satisfies:
x = L(x) - L(x)*L(q*x)/2! + L(x)*L(q*x)*L(q^2*x)/3! +- ...
and L(x) = x + 3/2!*x^2 + 27/3!*x^3 + 486/4!*x^4 + ... (A111844).
Thus the g.f. of column 0 of matrix power P^m is:
1 + m*L(x) + m^2/2!*L(x)*L(3*x) + m^3/3!*L(x)*L(3*x)*L(3^2*x) +
m^4/4!*L(x)*L(3*x)*L(3^2*x)*L(3^3*x) + ...
Triangle P begins:
1;
1,1;
3,3,1;
18,18,9,1;
216,216,135,27,1;
5589,5589,4050,1134,81,1;
336555,336555,269730,95256,9963,243,1; ...
where P^3 shifts columns left and up one place:
1;
3,1;
18,9,1;
216,135,27,1;
5589,4050,1134,81,1; ...
		

Crossrefs

Cf. A111841 (column 0), A111842 (row sums), A111843 (matrix log), A078122 (variant).

Programs

  • PARI
    {P(n,k,q=3) = my(A=Mat(1),B);if(nPaul D. Hanna, Jul 11 2025):
    for(n=0,10, for(k=0,n, print1(P(n,k),", ")); print(""))

Formula

Let q=3; the g.f. of column k of P^m (ignoring leading zeros) equals: 1 + Sum_{n>=1} (m*q^k)^n/n! * Product_{j=0..n-1} L(q^j*x) where L(x) satisfies: x = -Sum_{n>=1} Product_{j=0..n-1} -L(q^j*x)/(j+1); L(x) equals the g.f. of column 0 of the matrix log of P (A111844).

A111848 Matrix log of triangle A111845, which shifts columns left and up under matrix 4th power; these terms are the result of multiplying each element in row n and column k by (n-k)!.

Original entry on oeis.org

0, 1, 0, 4, 4, 0, 56, 16, 16, 0, 1728, 224, 64, 64, 0, -45696, 6912, 896, 256, 256, 0, -159401472, -182784, 27648, 3584, 1024, 1024, 0, 387212983296, -637605888, -731136, 110592, 14336, 4096, 4096, 0, 14722642769657856, 1548851933184, -2550423552, -2924544, 442368, 57344, 16384, 16384, 0
Offset: 0

Views

Author

Paul D. Hanna, Aug 23 2005

Keywords

Comments

Column k equals 4^k multiplied by column 0 (A111849) when ignoring zeros above the diagonal.

Examples

			Matrix log of A111845, with factorial denominators, begins:
0;
1/1!, 0;
4/2!, 4/1!, 0;
56/3!, 16/2!, 16/1!, 0;
1728/4!, 224/3!, 64/2!, 64/1!, 0;
-45696/5!, 6912/4!, 896/3!, 256/2!, 256/1!, 0; ...
		

Crossrefs

Cf. A111845 (triangle), A111849 (column 0), A111818 (variant).

Programs

  • PARI
    L(n,k,q=4)=local(A=Mat(1),B);if(n
    				

Formula

T(n, k) = 4^k*T(n-k, 0) = 4^k*A111844(n-k) for n>=k>=0.

A111843 Matrix log of triangle A111840, which shifts columns left and up under matrix cube; these terms are the result of multiplying each element in row n and column k by (n-k)!.

Original entry on oeis.org

0, 1, 0, 3, 3, 0, 27, 9, 9, 0, 486, 81, 27, 27, 0, 7776, 1458, 243, 81, 81, 0, -2423196, 23328, 4374, 729, 243, 243, 0, -97338996, -7269588, 69984, 13122, 2187, 729, 729, 0, 5883879500784, -292016988, -21808764, 209952, 39366, 6561, 2187, 2187, 0
Offset: 0

Views

Author

Paul D. Hanna, Aug 23 2005

Keywords

Comments

Column k equals 3^k multiplied by column 0 (A111844) when ignoring zeros above the diagonal.

Examples

			Matrix log of A111840, with factorial denominators, begins:
0;
1/1!, 0;
3/2!, 3/1!, 0;
27/3!, 9/2!, 9/1!, 0;
486/4!, 81/3!, 27/2!, 27/1!, 0;
7776/5!, 1458/4!, 243/3!, 81/2!, 81/1!, 0;
-2423196/6!, 23328/5!, 4374/4!, 729/3!, 243/2!, 243/1!, 0;
		

Crossrefs

Cf. A111840 (triangle), A111844 (column 0), A111815 (variant), A111941 (q=-1), A111810 (q=2), A111848 (q=4).

Programs

  • PARI
    T(n,k,q=3)=local(A=Mat(1),B);if(n
    				

Formula

T(n, k) = 3^k*T(n-k, 0) = 3^k*A111844(n-k) for n>=k>=0.

A111849 Column 0 of the matrix logarithm (A111848) of triangle A111845, which shifts columns left and up under matrix 4th power; these terms are the result of multiplying the element in row n by n!.

Original entry on oeis.org

0, 1, 4, 56, 1728, -45696, -159401472, 387212983296, 14722642769657856, -783395638188945997824, -571756408840959817330851840, 603349161280921866200339538247680, 8390141848229920894318007084122311229440
Offset: 0

Views

Author

Paul D. Hanna, Aug 23 2005

Keywords

Comments

Let q=4; the g.f. of column k of A111845^m (matrix power m) is: 1 + Sum_{n>=1} (m*q^k)^n/n! * Product_{j=0..n-1} A(q^j*x).

Examples

			E.g.f. A(x) = x + 4/2!*x^2 + 56/3!*x^3 + 1728/4!*x^4
- 45696/5!*x^5 - 159401472/6!*x^6 +...
where A(x) satisfies:
x = A(x) - A(x)*A(4*x)/2! + A(x)*A(4*x)*A(4^2*x)/3!
- A(x)*A(4*x)*A(4^2*x)*A(4^3*x)/4! + ...
also:
Let G(x) be the g.f. of A111846 (column 0 of A111845), then
G(x) = 1 + x + 4*x^2 + 40*x^3 + 1040*x^4 + 78240*x^5 +...
= 1 + A(x) + A(x)*A(4*x)/2! + A(x)*A(4*x)*A(4^2*x)/3!
+ A(x)*A(4*x)*A(4^2*x)*A(4^3*x)/4! +...
		

Crossrefs

Cf. A111848 (matrix log), A111845 (triangle), A111846, A111821 (variant), A111942 (q=-1), A111811 (q=2), A111844 (q=3).

Programs

  • PARI
    {a(n,q=4)=local(A=Mat(1),B);if(n<0,0, for(m=1,n+1,B=matrix(m,m);for(i=1,m, for(j=1,i, if(j==i,B[i,j]=1,if(j==1,B[i,j]=(A^q)[i-1,1], B[i,j]=(A^q)[i-1,j-1]));));A=B); B=sum(i=1,#A,-(A^0-A)^i/i);return(n!*B[n+1,1]))}

Formula

E.g.f. satisfies: x = Sum_{n>=1} -(-1)^n/n!*Prod_{j=0..n-1} A(4^j*x).
Showing 1-4 of 4 results.