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 1-3 of 3 results.

A114116 1's-counting matrix: row sums give number of 1's in binary expansion of n+1.

Original entry on oeis.org

1, 0, 1, 2, -1, 1, -1, 2, -1, 1, 1, 0, 1, -1, 1, 1, 0, 0, 1, -1, 1, 3, -2, 2, -1, 1, -1, 1, -2, 3, -2, 2, -1, 1, -1, 1, 0, 1, 0, 0, 1, -1, 1, -1, 1, 0, 1, 0, 0, 0, 1, -1, 1, -1, 1, 2, -1, 2, -2, 2, -1, 1, -1, 1, -1, 1, 0, 1, -1, 2, -2, 2, -1, 1, -1, 1, -1, 1, 2, -1, 1, 0, 0, 0, 1, -1, 1, -1, 1, -1, 1, 2, -1, 1, 0, 0, 0, 0, 1, -1, 1, -1, 1, -1, 1, 4, -3, 3, -2, 2
Offset: 0

Views

Author

Paul Barry, Nov 13 2005

Keywords

Comments

First column is -A037861(n+1). Row sums are A000120. Product of partial sum matrix (1/(1-x),x) and A114115. Inverse is A114117.

Examples

			Triangle begins
1;
0, 1;
2,-1, 1;
-1, 2,-1, 1;
1, 0, 1,-1, 1;
1, 0, 0, 1,-1, 1;
3,-2, 2,-1, 1,-1, 1;
		

A114117 Inverse of 1's counting matrix A114116.

Original entry on oeis.org

1, 0, 1, -2, 1, 1, -1, -1, 1, 1, 0, -2, 0, 1, 1, 0, -1, -1, 0, 1, 1, 0, 0, -2, 0, 0, 1, 1, 0, 0, -1, -1, 0, 0, 1, 1, 0, 0, 0, -2, 0, 0, 0, 1, 1, 0, 0, 0, -1, -1, 0, 0, 0, 1, 1, 0, 0, 0, 0, -2, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, -1, -1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, -1, -1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, -2, 0, 0, 0, 0, 0, 0, 1, 1
Offset: 0

Views

Author

Paul Barry, Nov 13 2005

Keywords

Comments

Row sums are (1,1,0,0,0,.....) with g.f. 1+x. Diagonal sums have g.f. (1-x^2-x^3)/(1-x^3). Product of A114115 and the first difference matrix (1-x,x).

Examples

			Triangle begins
  1;
  0, 1;
 -2, 1, 1;
 -1,-1, 1, 1;
  0,-2, 0, 1, 1;
  0,-1,-1, 0, 1, 1;
  0, 0,-2, 0, 0, 1, 1;
  0, 0,-1,-1, 0, 0, 1, 1;
		

Crossrefs

Formula

T(n, k) = Sum_{j=0..n} Sum_{i=0..n} C(floor((n+i)/2), j)*C(j, floor((n+i)/2))*(2*C(0, j-k)-C(1, j-k)).

A114114 An invertible partition matrix.

Original entry on oeis.org

1, 1, 1, 0, 2, 1, 0, 1, 2, 1, 0, 0, 2, 2, 1, 0, 0, 1, 2, 2, 1, 0, 0, 0, 2, 2, 2, 1, 0, 0, 0, 1, 2, 2, 2, 1, 0, 0, 0, 0, 2, 2, 2, 2, 1, 0, 0, 0, 0, 1, 2, 2, 2, 2, 1, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 1, 0, 0, 0, 0, 0, 1, 2, 2, 2, 2, 2, 1, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 2, 1
Offset: 0

Views

Author

Paul Barry, Nov 13 2005

Keywords

Comments

Row sums are n+1, A000027. Diagonal sums are 1,1,1,2,2,2,3,3,3,.... or A008620. Inverse is A114115. Product with first difference matrix (1-x,x) is A114117.

Examples

			Triangle begins
1.................=1
1,1...............=2
0,2,1.............=3
0,1,2,1...........=4
0,0,2,2,1.........=5
0,0,1,2,2,1.......=6
0,0,0,2,2,2,1.....=7
0,0,0,1,2,2,2,1...=8
		

Formula

Number triangle T(n, k)=sum{j=0..n, C(floor((n+j)/2), k)C(k, floor((n+j)/2))}.
Showing 1-3 of 3 results.