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.

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A136230 Triangle V, read by rows, where column k of V^(j+1) = column j of P^(3k+2), for j>=0, k>=0 and where P=A136220.

Original entry on oeis.org

1, 2, 1, 8, 5, 1, 49, 35, 8, 1, 414, 325, 80, 11, 1, 4529, 3820, 988, 143, 14, 1, 61369, 54800, 14696, 2200, 224, 17, 1, 996815, 932761, 257264, 39468, 4123, 323, 20, 1, 18931547, 18426632, 5198680, 812801, 86506, 6919, 440, 23, 1, 412345688
Offset: 0

Views

Author

Paul D. Hanna, Jan 28 2008

Keywords

Examples

			This triangle V begins:
1;
2, 1;
8, 5, 1;
49, 35, 8, 1;
414, 325, 80, 11, 1;
4529, 3820, 988, 143, 14, 1;
61369, 54800, 14696, 2200, 224, 17, 1;
996815, 932761, 257264, 39468, 4123, 323, 20, 1;
18931547, 18426632, 5198680, 812801, 86506, 6919, 440, 23, 1; ...
where column k of V = column 0 of P^(3k+2) and
triangle P = A136220 begins:
1;
1, 1;
3, 2, 1;
15, 10, 3, 1;
108, 75, 21, 4, 1;
1036, 753, 208, 36, 5, 1;
12569, 9534, 2637, 442, 55, 6, 1; ...
where column k of P^2 = column 0 of V^(k+1).
Also, this triangle V equals the matrix product:
V = P^2 * [P shift right one column]
where P^2 = A136225 begins:
1;
2, 1;
8, 4, 1;
49, 26, 6, 1;
414, 232, 54, 8, 1;
4529, 2657, 629, 92, 10, 1;
61369, 37405, 9003, 1320, 140, 12, 1; ...
and P shift right one column begins:
1;
0, 1;
0, 1, 1;
0, 3, 2, 1;
0, 15, 10, 3, 1;
0, 108, 75, 21, 4, 1;
0, 1036, 753, 208, 36, 5, 1; ...
Also, this triangle V equals the matrix product:
V = U * [U shift down one row]
where triangle U = A136228 begins:
1;
1, 1;
3, 4, 1;
15, 24, 7, 1;
108, 198, 63, 10, 1;
1036, 2116, 714, 120, 13, 1; ...
and U shift down one row begins:
1;
1, 1;
1, 1, 1;
3, 4, 1, 1;
15, 24, 7, 1, 1;
108, 198, 63, 10, 1, 1;
1036, 2116, 714, 120, 13, 1, 1; ...
		

Crossrefs

Cf. A136226 (column 0), A136229 (column 1); related tables: A136220 (P), A136225 (P^2), A136230 (V), A136231 (W=P^3), A136234 (V^2), A136237 (V^3); A136217, A136218.

Programs

  • PARI
    {T(n,k)=local(P=Mat(1),U=Mat(1),V=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])))); U=P*PShR^2;V=P^2*PShR; U=matrix(#P+1, #P+1, r,c, if(r>=c, if(r<#P+1,U[r,c], if(c==1,(P^3)[ #P,1],(P^(3*c-1))[r-c+1,1])))); V=matrix(#P+1, #P+1, r,c, if(r>=c, if(r<#P+1,V[r,c], if(c==1,(P^3)[ #P,1],(P^(3*c-2))[r-c+1,1])))); P=matrix(#U, #U, r,c, if(r>=c, if(r<#R,P[r,c], (U^c)[r-c+1,1])))));V[n+1,k+1]}

Formula

Triangle W=P^3=A136231 transforms column k of V into column k+1 of V. This triangle equals the matrix products: V = P^2 * [P shift right one column] and V = U * [U shift down one row] (see examples).

A136234 Matrix square of triangle V = A136230, read by rows.

Original entry on oeis.org

1, 4, 1, 26, 10, 1, 232, 110, 16, 1, 2657, 1435, 248, 22, 1, 37405, 22135, 4240, 440, 28, 1, 627435, 397820, 81708, 9295, 686, 34, 1, 12248365, 8203057, 1773156, 214478, 17248, 986, 40, 1, 273211787, 191405232, 43039532, 5442349, 463267, 28747, 1340
Offset: 0

Views

Author

Paul D. Hanna, Feb 07 2008

Keywords

Examples

			This triangle, V^2, begins:
1;
4, 1;
26, 10, 1;
232, 110, 16, 1;
2657, 1435, 248, 22, 1;
37405, 22135, 4240, 440, 28, 1;
627435, 397820, 81708, 9295, 686, 34, 1;
12248365, 8203057, 1773156, 214478, 17248, 986, 40, 1;
273211787, 191405232, 43039532, 5442349, 463267, 28747, 1340, 46, 1; ...
where column 0 of V^2 = column 1 of P^2 = triangle A136225.
		

Crossrefs

Cf. A136227 (column 0); related tables: A136220 (P), A136228 (U), A136230 (V), A136231 (W=P^3), A136237 (V^3).

Programs

  • PARI
    {T(n,k)=local(P=Mat(1),U=Mat(1),V=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])))); U=P*PShR^2;V=P^2*PShR; U=matrix(#P+1, #P+1, r,c, if(r>=c, if(r<#P+1,U[r,c], if(c==1,(P^3)[ #P,1],(P^(3*c-1))[r-c+1,1])))); V=matrix(#P+1, #P+1, r,c, if(r>=c, if(r<#P+1,V[r,c], if(c==1,(P^3)[ #P,1],(P^(3*c-2))[r-c+1,1])))); P=matrix(#U, #U, r,c, if(r>=c, if(r<#R,P[r,c], (U^c)[r-c+1,1]))))); (V^2)[n+1,k+1]}

Formula

Column k of V^2 (this triangle) = column 1 of P^(3k+2), where P = triangle A136220.
Showing 1-2 of 2 results.