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.

A185628 Triangle, read by rows, equal to the matrix cube of triangle A185620.

Original entry on oeis.org

1, 3, 1, 6, 3, 1, 16, 12, 3, 1, 60, 55, 18, 3, 1, 305, 315, 118, 24, 3, 1, 1988, 2243, 912, 205, 30, 3, 1, 15951, 19378, 8342, 1995, 316, 36, 3, 1, 153171, 198363, 89193, 22274, 3708, 451, 42, 3, 1, 1722693, 2358860, 1098552, 283427, 48863, 6195, 610, 48, 3, 1, 22296396, 32060736
Offset: 0

Views

Author

Paul D. Hanna, Sep 07 2011

Keywords

Examples

			 Triangle begins:
1;
3, 1;
6, 3, 1;
16, 12, 3, 1;
60, 55, 18, 3, 1;
305, 315, 118, 24, 3, 1;
1988, 2243, 912, 205, 30, 3, 1;
15951, 19378, 8342, 1995, 316, 36, 3, 1;
153171, 198363, 89193, 22274, 3708, 451, 42, 3, 1;
1722693, 2358860, 1098552, 283427, 48863, 6195, 610, 48, 3, 1;
22296396, 32060736, 15376126, 4070883, 720586, 94085, 9600, 793, 54, 3, 1; ...
This triangle equals the matrix cube, R^3, of triangle R = A185620, which begins:
1;
1, 1;
1, 1, 1;
1, 3, 1, 1;
1, 10, 5, 1, 1;
1, 42, 27, 7, 1, 1;
1, 226, 173, 52, 9, 1, 1;
1, 1525, 1330, 442, 85, 11, 1, 1;
1, 12555, 12134, 4345, 897, 126, 13, 1, 1; ...
where R^3 - R^2 + I equals R shifted left one column.
		

Crossrefs

A185629 Column 0 of triangle A185628; also, equals row sums of triangle A185624.

Original entry on oeis.org

1, 3, 6, 16, 60, 305, 1988, 15951, 153171, 1722693, 22296396, 327270440, 5381716953, 98134088419, 1967105567802, 43024511648982, 1020235144731236, 26083065249549660, 715430961891290714, 20962974995245684878, 653654392800091507791, 21615444263990028093227
Offset: 0

Views

Author

Paul D. Hanna, Sep 07 2011

Keywords

Comments

Triangle A185628 equals the matrix cube of triangle R = A185620, which satisfies: R^3 - R^2 + I = R shifted left one column.

Crossrefs

Programs

  • PARI
    {a(n)=local(A=Mat(1), B); for(m=1, n+1, B=A^3-A^2+A^0; A=matrix(m+1, m+1); for(i=1, m+1, for(j=1, i, if(i<2|j==i, A[i, j]=1, if(j==1, A[i, j]=1, A[i, j]=B[i-1, j-1]))))); return((A^3)[n+1, 1])}

A185631 Row sums of triangle A185628.

Original entry on oeis.org

1, 4, 10, 32, 137, 766, 5382, 46022, 467206, 5519252, 74629263, 1139283601, 19411643752, 365595475542, 7548810986515, 169681672611815, 4126880020198630, 108026180912533227, 3029184083924476085, 90617948406514693702, 2881333799993441893564, 97057552263114611503090
Offset: 0

Views

Author

Paul D. Hanna, Sep 07 2011

Keywords

Comments

Triangle A185628 equals the matrix cube of triangle R = A185620, which satisfies: R^3 - R^2 + I = R shifted left one column.

Crossrefs

Programs

  • PARI
    {a(n)=local(A=Mat(1), B); for(m=1, n+1, B=A^3-A^2+A^0; A=matrix(m+1, m+1); for(i=1, m+1, for(j=1, i, if(i<2||j==i, A[i, j]=1, if(j==1, A[i, j]=1, A[i, j]=B[i-1, j-1]))))); return(sum(k=1,n+1,(A^3)[n+1, k]))}
Showing 1-3 of 3 results.