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.

A055326 Column 1 of triangle A055325.

Original entry on oeis.org

1, -1, 3, -23, 425, -18129, 1721419, -353654167, 153923102577, -139765654884545, 261831303051976691, -1003756293946036677111, 7827579773381983088436313, -123626888505819540001029957073
Offset: 1

Views

Author

Christian G. Bower, May 12 2000

Keywords

A162498 Triangle read by rows: T(n, k) = Sum_{j=0..k} (-1)^j*binomial(n, j)*(k + 1 - j)^(n - 1).

Original entry on oeis.org

1, 1, 1, 3, 4, 1, 23, 33, 11, 1, 425, 620, 220, 26, 1, 18129, 26525, 9520, 1180, 57, 1, 1721419, 2519664, 905765, 113050, 5649, 120, 1, 353654167, 517670461, 186123259, 23248085, 1166221, 25347, 247, 1, 153923102577, 225309742552, 81009042744, 10119247684, 507795498, 11059468, 109386, 502, 1
Offset: 1

Views

Author

Roger L. Bagula and Mats Granvik, Dec 06 2009

Keywords

Examples

			Triangle begins:
  {1},
  {1, 1},
  {3, 4, 1},
  {23, 33, 11, 1},
  {425, 620, 220, 26, 1},
  {18129, 26525, 9520, 1180, 57, 1},
  {1721419, 2519664, 905765, 113050, 5649, 120, 1},
  {353654167, 517670461, 186123259, 23248085, 1166221, 25347, 247, 1},
  {153923102577, 225309742552, 81009042744, 10119247684, 507795498, 11059468, 109386, 502, 1},
  ...
		

Crossrefs

Cf. A154921. An unsigned version of A055325.

Programs

  • Mathematica
    t[n_,k_]:=Sum[(-1)^j Binomial[n,j](k+1-j)^(n-1),{j,0,k}];
    M[n_]:=Table[If[k <= m,(-1)^(m+k)*t[m,k],0],{k,0,n-2},{m,2,n}];
    Flatten[Table[Table[Inverse[M[12]][[m,n]],{m,1,n}],{n,1,11}]]

A171273 Matrix inverse of A060187.

Original entry on oeis.org

1, 1, 1, 5, 6, 1, 93, 115, 23, 1, 5993, 7436, 1518, 76, 1, 1272089, 1578757, 322762, 16330, 237, 1, 857402029, 1064110290, 217560951, 11012540, 160571, 722, 1, 1792650585525, 2224835452407, 454875884137, 23025275075, 335768223, 1512581, 2179, 1
Offset: 1

Views

Author

Roger L. Bagula and Mats Granvik, Dec 06 2009

Keywords

Examples

			{1},
{1, 1},
{5, 6, 1},
{93, 115, 23, 1},
{5993, 7436, 1518, 76, 1},
{1272089, 1578757, 322762, 16330, 237, 1},
{857402029, 1064110290, 217560951, 11012540, 160571, 722, 1},
{1792650585525, 2224835452407, 454875884137, 23025275075, 335768223, 1512581, 2179, 1},
{11464255554367057, 14228139328931096, 2908996087466828, 147249943814184, 2147290464886, 9673492136, 13945196, 6552, 1},
{222406320165016449457, 276025608122908733321, 56434463826320585284, 2856645864675796564, 41657391444153086, 187665608020478, 270538484020, 127141156, 19673, 1},
{13026233415367869864109781, 16166689855580307839632286, 3305339964838291288943901, 167312402773377971746920, 2439853795947184617546, 10991486289326969076, 15845312257310658, 7446608913000, 1152338433, 59038, 1}
		

Crossrefs

Programs

  • Mathematica
    m = 2;
    A[n_, 1] := 1
    A[n_, n_] := 1
    A[n_, k_] := (m*n - m*k + 1)A[n - 1, k - 1] + (m*k - (m - 1))A[n - 1, k]
    a = Table[A[n, k], {n, 12}, {k, n}]
    M[n_] := Table[If[k <= m, (-1)^(m + k)*a[[m, k]], 0], {k, 1, n}, {m, 1, n}]
    Table[Table[Inverse[M[12]][[m, n]], {m, 1, n}], {n, 1, 11}]
    Flatten[%]

Formula

A(n,k) = (m*n - m*k + 1) * A(n - 1, k - 1) + (m*k - (m - 1)) * A(n - 1, k), A(n,1) = A(n,n) = 1.
Showing 1-3 of 3 results.