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.

A135890 Column 1 of triangle A135888, which equals the matrix cube of triangle A135880; also equals column 1 of triangle A135895.

Original entry on oeis.org

1, 6, 39, 300, 2741, 29380, 363922, 5135894, 81557270, 1441771540, 28114817877, 600012111858, 13919315033624, 348932593149877, 9403371859278914, 271183690566871863, 8335374900994682248, 272083236017290793444
Offset: 0

Views

Author

Paul D. Hanna, Dec 15 2007

Keywords

Crossrefs

Cf. A135888, A135889; A135880, A135895.

Programs

  • PARI
    {a(n)=local(P=Mat(1),R,PShR);if(n==0,1,for(i=0,n+1, PShR=matrix(#P,#P, r,c, if(r>=c,if(r==c,1,if(c==1,0,P[r-1,c-1]))));R=P*PShR; R=matrix(#P+1, #P+1, r,c, if(r>=c, if(r<#P+1,R[r,c], if(c==1,(P^2)[ #P,1],(P^(2*c-1))[r-c+1,1])))); P=matrix(#R, #R, r,c, if(r>=c, if(r<#R,P[r,c], (R^c)[r-c+1,1]))));(P^3)[n+2,2])}

A135894 Triangle R, read by rows, where column k of R equals column 0 of P^(2k+1) where P=A135880.

Original entry on oeis.org

1, 1, 1, 2, 3, 1, 6, 12, 5, 1, 25, 63, 30, 7, 1, 138, 421, 220, 56, 9, 1, 970, 3472, 1945, 525, 90, 11, 1, 8390, 34380, 20340, 5733, 1026, 132, 13, 1, 86796, 399463, 247066, 72030, 13305, 1771, 182, 15, 1, 1049546, 5344770, 3430936, 1028076, 194646, 26565, 2808
Offset: 0

Views

Author

Paul D. Hanna, Dec 15 2007

Keywords

Comments

Triangle P = A135880 is defined by: column k of P^2 equals column 0 of P^(2k+2) such that column 0 of P^2 equals column 0 of P shift left.

Examples

			Triangle R begins:
1;
1, 1;
2, 3, 1;
6, 12, 5, 1;
25, 63, 30, 7, 1;
138, 421, 220, 56, 9, 1;
970, 3472, 1945, 525, 90, 11, 1;
8390, 34380, 20340, 5733, 1026, 132, 13, 1;
86796, 399463, 247066, 72030, 13305, 1771, 182, 15, 1;
1049546, 5344770, 3430936, 1028076, 194646, 26565, 2808, 240, 17, 1;
14563135, 81097517, 53741404, 16477041, 3182778, 442948, 47801, 4185, 306, 19, 1; ...
where column k of R equals column 0 of P^(2k+1) for k>=0,
and P = A135880 begins:
1;
1, 1;
2, 2, 1;
6, 7, 3, 1;
25, 34, 15, 4, 1;
138, 215, 99, 26, 5, 1;
970, 1698, 814, 216, 40, 6, 1; ...
where column k of P equals column 0 of R^(k+1).
The matrix product P^-1*R = A135898 = P (shifted right one column);
the matrix product R^-1*P^2 = A135900 = R (shifted down one row).

Crossrefs

Cf. A135881 (column 0), A135889 (column 1); A135880 (P), A135885 (Q=P^2), A135895 (R^2), A135896 (R^3), A135897 (R^4); A135888 (P^3) A135892 (P^5); A135898 (P^-1*R), A135899 (P*R^-1*P), A135900 (R^-1*Q).

Programs

  • PARI
    {T(n,k)=local(P=Mat(1),R=Mat(1),PShR);if(n>0,for(i=0,n, PShR=matrix(#P,#P, r,c, if(r>=c,if(r==c,1,if(c==1,0,P[r-1,c-1]))));R=P*PShR; R=matrix(#P+1, #P+1, r,c, if(r>=c, if(r<#P+1,R[r,c], if(c==1,(P^2)[ #P,1],(P^(2*c-1))[r-c+1,1])))); P=matrix(#R, #R, r,c, if(r>=c, if(r<#R,P[r,c], (R^c)[r-c+1,1])))));R[n+1,k+1]}

Formula

Column k of R = column 0 of P^(2k+1) for k>=0 where triangle P = A135880; column 0 of R = column 0 of P; column 1 of R = column 0 of P^3; column 2 of R = column 0 of P^5. See more formulas relating triangles P, Q and R, in entry A135880.

Extensions

Typo in formula corrected by Paul D. Hanna, Mar 26 2010

A135892 Triangle, read by rows, equal to P^5, where triangle P = A135880.

Original entry on oeis.org

1, 5, 1, 30, 10, 1, 220, 95, 15, 1, 1945, 990, 195, 20, 1, 20340, 11635, 2625, 330, 25, 1, 247066, 154450, 38270, 5440, 500, 30, 1, 3430936, 2302142, 611525, 94515, 9750, 705, 35, 1, 53741404, 38229214, 10721093, 1761940, 196500, 15870, 945, 40, 1
Offset: 0

Views

Author

Paul D. Hanna, Dec 15 2007

Keywords

Comments

Triangle P = A135880 is defined by: column k of P^2 equals column 0 of P^(2k+2) such that column 0 of P^2 equals column 0 of P shift left.

Examples

			Triangle P^5 begins:
1;
5, 1;
30, 10, 1;
220, 95, 15, 1;
1945, 990, 195, 20, 1;
20340, 11635, 2625, 330, 25, 1;
247066, 154450, 38270, 5440, 500, 30, 1;
3430936, 2302142, 611525, 94515, 9750, 705, 35, 1;
53741404, 38229214, 10721093, 1761940, 196500, 15870, 945, 40, 1;
938816814, 701685738, 205607124, 35429974, 4182295, 363820, 24115, 1220, 45, 1;
where P = A135880 begins:
1;
1, 1;
2, 2, 1;
6, 7, 3, 1;
25, 34, 15, 4, 1;
138, 215, 99, 26, 5, 1;
970, 1698, 814, 216, 40, 6, 1; ...
in which column k of P = column 0 of R^(k+1),
where R = A135894 begins:
1;
1, 1;
2, 3, 1;
6, 12, 5, 1;
25, 63, 30, 7, 1;
138, 421, 220, 56, 9, 1;
970, 3472, 1945, 525, 90, 11, 1; ...
in which column k of R equals column 0 of P^(2k+1).

Crossrefs

Cf. A135880 (P), A135894 (R), A135895 (R^2), A135896 (R^3), A135897 (R^4).

Programs

  • PARI
    {T(n,k)=local(P=Mat(1),R,PShR);if(n>0,for(i=0,n, PShR=matrix(#P,#P, r,c, if(r>=c,if(r==c,1,if(c==1,0,P[r-1,c-1]))));R=P*PShR; R=matrix(#P+1, #P+1, r,c, if(r>=c, if(r<#P+1,R[r,c], if(c==1,(P^2)[ #P,1],(P^(2*c-1))[r-c+1,1])))); P=matrix(#R, #R, r,c, if(r>=c, if(r<#R,P[r,c], (R^c)[r-c+1,1])))));(P^5)[n+1,k+1]}

Formula

Column k of P^5 = column 2 of R^(k+1) for k>=0 where triangle R = A135894; column 0 of P^5 = column 2 of R; column 1 of P^5 = column 2 of R^2; column 2 of P^5 = column 2 of R^3; column 3 of P^5 = column 2 of R^4.
Showing 1-3 of 3 results.

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