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.

A174486 Column 0 of triangle A174485.

Original entry on oeis.org

1, 1, 5, 70, 1973, 94216, 6851197, 706335064, 98105431657, 17669939141440, 4006704580744601, 1117139031649249984, 375701872315954792093, 149988716080978525265776, 70129434038848683974552365
Offset: 0

Views

Author

Paul D. Hanna, Apr 18 2010

Keywords

Comments

Triangular matrix described by A174485 transforms diagonals of the array A174480 of coefficients of successive iterations of x*exp(x).

Crossrefs

Programs

  • PARI
    {a(n,k=0)=local(F=x, xEx=x*exp(x+x*O(x^(n+k+1))), M, N, P, m=n+k); M=matrix(m+2, m+2, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, xEx)); polcoeff(F, c)); N=matrix(m+1, m+1, r, c, M[r, c]); P=matrix(m+1, m+1, r, c, M[r+1, c]); n!*(P~*N~^-1)[n+k+1, k+1]}

A174487 Column 1 of triangle A174485.

Original entry on oeis.org

1, 2, 16, 308, 11048, 639972, 54671188, 6471586298, 1014487323984, 203492881479464, 50842872702666524, 15484223252089602342, 5646860009850046968472, 2429577079632942917710580
Offset: 0

Views

Author

Paul D. Hanna, Apr 18 2010

Keywords

Comments

Triangular matrix described by A174485 transforms diagonals of the array A174480 of coefficients of successive iterations of x*exp(x).

Crossrefs

Programs

  • PARI
    {a(n,k=1)=local(F=x, xEx=x*exp(x+x*O(x^(n+k+1))), M, N, P, m=n+k); M=matrix(m+2, m+2, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, xEx)); polcoeff(F, c)); N=matrix(m+1, m+1, r, c, M[r, c]); P=matrix(m+1, m+1, r, c, M[r+1, c]); n!*(P~*N~^-1)[n+k+1, k+1]}

A174488 Column 2 of triangle A174485.

Original entry on oeis.org

1, 3, 33, 810, 35325, 2408568, 236624733, 31654735416, 5532363865977, 1223887080470256, 334272773792556369, 110467177430468340408, 43442224822360939240629, 20048090531903711663566248
Offset: 0

Views

Author

Paul D. Hanna, Apr 18 2010

Keywords

Comments

Triangular matrix described by A174485 transforms diagonals of the array A174480 of coefficients of successive iterations of x*exp(x).

Crossrefs

Programs

  • PARI
    {a(n,k=2)=local(F=x, xEx=x*exp(x+x*O(x^(n+k+1))), M, N, P, m=n+k); M=matrix(m+2, m+2, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, xEx)); polcoeff(F, c)); N=matrix(m+1, m+1, r, c, M[r, c]); P=matrix(m+1, m+1, r, c, M[r+1, c]); n!*(P~*N~^-1)[n+k+1, k+1]}

A174489 Column 3 of triangle A174485.

Original entry on oeis.org

1, 4, 56, 1672, 85904, 6741544, 749040472, 111786940612, 21558649749088, 5215883627856592, 1546429233541304456, 551278120123210461436, 232603216443181020788944, 114634034948809175011787176
Offset: 0

Views

Author

Paul D. Hanna, Apr 18 2010

Keywords

Comments

Triangular matrix described by A174485 transforms diagonals of the array A174480 of coefficients of successive iterations of x*exp(x).

Crossrefs

Programs

  • PARI
    {a(n,k=3)=local(F=x, xEx=x*exp(x+x*O(x^(n+k+1))), M, N, P, m=n+k); M=matrix(m+2, m+2, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, xEx)); polcoeff(F, c)); N=matrix(m+1, m+1, r, c, M[r, c]); P=matrix(m+1, m+1, r, c, M[r+1, c]); n!*(P~*N~^-1)[n+k+1, k+1]}

A174480 Rectangular array of coefficients in successive iterations of x*exp(x), as read by antidiagonals.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 6, 1, 1, 4, 15, 23, 1, 1, 5, 28, 102, 104, 1, 1, 6, 45, 274, 861, 537, 1, 1, 7, 66, 575, 3400, 8598, 3100, 1, 1, 8, 91, 1041, 9425, 50734, 98547, 19693, 1, 1, 9, 120, 1708, 21216, 187455, 880312, 1270160, 136064, 1, 1, 10, 153, 2612, 41629
Offset: 1

Views

Author

Paul D. Hanna, Apr 17 2010

Keywords

Comments

Triangle A174485 forms a matrix that transforms a diagonal into an adjacent diagonal in this array.

Examples

			Form an array of coefficients in the iterations of x*exp(x), which begin:
n=1: [1, 1, 1/2!, 1/3!, 1/4!, 1/5!, 1/6!, ...];
n=2: [1, 2, 6/2!, 23/3!, 104/4!, 537/5!, 3100/6!, ...];
n=3: [1, 3, 15/2!, 102/3!, 861/4!, 8598/5!, 98547/6!, ...];
n=4: [1, 4, 28/2!, 274/3!, 3400/4!, 50734/5!, 880312/6!, ...];
n=5: [1, 5, 45/2!, 575/3!, 9425/4!, 187455/5!, 4367245/6!, ...];
n=6: [1, 6, 66/2!, 1041/3!, 21216/4!, 527631/5!, 15441636/6!, ...];
n=7: [1, 7, 91/2!, 1708/3!, 41629/4!, 1242892/5!, 43806175/6!, ...];
n=8: [1, 8, 120/2!, 2612/3!, 74096/4!, 2582028/5!, 106459312/6!, ...];
n=9: [1, 9, 153/2!, 3789/3!, 122625/4!, 4885389/5!, 230689017/6!, ...];
n=10:[1, 10, 190/2!, 5275/3!, 191800/4!, 8599285/5!, 457584940/6!,...];
...
This array begins with the above unreduced numerators for n >= 1, k >= 1.
		

Crossrefs

Cf. A174485, diagonals: A174481, A174482, A174483, A174484.

Programs

  • PARI
    {T(n, k)=local(F=x, xEx=x*exp(x+x*O(x^(k+1)))); for(i=1,n,F=subst(F, x, xEx));(k-1)!*polcoeff(F, k)}

Formula

T(n,k) = [x^k/(k-1)! ] G_{n}(x) where G_{n}(x) = G_{n-1}(x*exp(x)) with G_0(x)=x, for n>=1, k>=1.
Showing 1-5 of 5 results.