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 1-5 of 5 results.

A152401 Column 1 of triangle A152400; also, column 1 of square array A152405.

Original entry on oeis.org

1, 2, 8, 45, 318, 2671, 25805, 280609, 3381993, 44658052, 640279918, 9895457035, 163871617543, 2893296199441, 54230087607409, 1075060346670798, 22467666780553040, 493590689966427930, 11369641989418301977
Offset: 0

Views

Author

Paul D. Hanna, Dec 05 2008

Keywords

Comments

Matrix powers of triangle T=A152400 satisfy: column k of T^(j+1) = column j of T^(k+1) for all j>=0, k>=0.

Crossrefs

A152404 Column 1 of matrix square of triangle A152400; also, column 3 of square array A152405.

Original entry on oeis.org

1, 4, 22, 152, 1251, 11869, 126987, 1508209, 19651299, 278321523, 4253151796, 69700149063, 1218679465845, 22634882689433, 444893598200458, 9223269744306877, 201091581942120957, 4598872183673896769
Offset: 0

Views

Author

Paul D. Hanna, Dec 05 2008

Keywords

Comments

Matrix powers of triangle T=A152400 satisfy:
column k of T^(j+1) = column j of T^(k+1) for all j>=0, k>=0.

Crossrefs

A152400 Triangle T, read by rows, where column k of T = column 0 of matrix power T^(k+1) for k>0, with column 0 of T = unsigned column 0 of T^-1 (shifted).

Original entry on oeis.org

1, 1, 1, 3, 2, 1, 14, 8, 3, 1, 86, 45, 15, 4, 1, 645, 318, 99, 24, 5, 1, 5662, 2671, 794, 182, 35, 6, 1, 56632, 25805, 7414, 1636, 300, 48, 7, 1, 633545, 280609, 78507, 16844, 2990, 459, 63, 8, 1, 7820115, 3381993, 926026, 194384, 33685, 5026, 665, 80, 9, 1
Offset: 0

Views

Author

Paul D. Hanna, Dec 05 2008

Keywords

Examples

			Triangle T begins:
1;
1, 1;
3, 2, 1;
14, 8, 3, 1;
86, 45, 15, 4, 1;
645, 318, 99, 24, 5, 1;
5662, 2671, 794, 182, 35, 6, 1;
56632, 25805, 7414, 1636, 300, 48, 7, 1;
633545, 280609, 78507, 16844, 2990, 459, 63, 8, 1;
7820115, 3381993, 926026, 194384, 33685, 5026, 665, 80, 9, 1;...
where column k of T = column 0 of T^(k+1) for k>0
and column 0 of T = unsigned column 0 of T^-1 (shifted).
Amazingly, column k of T^(j+1) = column j of T^(k+1) for j>=0, k>=0.
Matrix inverse T^-1 begins:
1;
-1, 1;
-1, -2, 1;
-3, -2, -3, 1;
-14, -7, -3, -4, 1;
-86, -37, -12, -4, -5, 1;
-645, -252, -71, -18, -5, -6, 1;...
where unsigned column 0 of T^-1 = column 0 of T (shifted).
Matrix square T^2 begins:
1;
2, 1;
8, 4, 1;
45, 22, 6, 1;
318, 152, 42, 8, 1;
2671, 1251, 345, 68, 10, 1;
25805, 11869, 3253, 648, 100, 12, 1;
280609, 126987, 34546, 6898, 1085, 138, 14, 1;...
where column 0 of T^2 = column 1 of T,
and column 2 of T^2 = column 1 of T^3.
Matrix cube T^3 begins:
1;
3, 1;
15, 6, 1;
99, 42, 9, 1;
794, 345, 81, 12, 1;
7414, 3253, 798, 132, 15, 1;
78507, 34546, 8679, 1518, 195, 18, 1;
926026, 407171, 103707, 18734, 2565, 270, 21, 1;...
where column 0 of T^3 = column 2 of T,
and column 3 of T^3 = column 2 of T^4.
Matrix power T^4 begins:
1;
4, 1;
24, 8, 1;
182, 68, 12, 1;
1636, 648, 132, 16, 1;
16844, 6898, 1518, 216, 20, 1;
194384, 81218, 18734, 2912, 320, 24, 1;
2476868, 1047638, 249202, 40932, 4950, 444, 28, 1;...
where column 0 of T^4 = column 3 of T,
and column 2 of T^4 = column 3 of T^3.
Related triangle A127714 begins:
1;
1, 1, 1;
1, 2, 2, 3, 3, 3;
1, 3, 5, 5, 8, 11, 11, 14, 14, 14;
1, 4, 9, 14, 14, 22, 33, 44, 44, 58, 72, 72, 86, 86, 86;...
where right border = column 0 of this triangle A152400.
		

Crossrefs

Cf. related triangles: A152405, A127714.

Programs

  • PARI
    T(n, k)=if(k>n || n<0,0, if(k==n,1, if(k==0,sum(j=1,n,T(n,j)*T(j-1,0)), sum(j=0,n-k,T(n-k, j)*T(j+k-1, k-1)));))

Formula

Column k of T^(j+1) = column j of T^(k+1) for all j>=0, k>=0.
Column k: T(n,k) = Sum_{j=0..n-k} T(n-k,j)*T(j+k-1,k-1) for n>=k>0.
Column 0: T(n,0) = Sum_{j=1..n} T(n,j)*T(j-1,0) for n>=0.

A152402 Column 2 of triangle A152400.

Original entry on oeis.org

1, 3, 15, 99, 794, 7414, 78507, 926026, 12010188, 169580899, 2586371577, 42336163519, 739814864633, 13739211766050, 270108101356162, 5602446487013365, 122232180232983149, 2797753890784828302
Offset: 0

Views

Author

Paul D. Hanna, Dec 05 2008

Keywords

Comments

Matrix powers of triangle T=A152400 satisfy:
column k of T^(j+1) = column j of T^(k+1) for all j>=0, k>=0.

Crossrefs

A152403 Column 3 of triangle A152400.

Original entry on oeis.org

1, 4, 24, 182, 1636, 16844, 194384, 2476868, 34461956, 519070980, 8405444924, 145502477888, 2679656009072, 52289220500822, 1077289873778412, 23361106832257087, 531744673834247758, 12673569230875132668
Offset: 0

Views

Author

Paul D. Hanna, Dec 05 2008

Keywords

Comments

Matrix powers of triangle T=A152400 satisfy:
column k of T^(j+1) = column j of T^(k+1) for all j>=0, k>=0.

Crossrefs

Showing 1-5 of 5 results.