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 1-10 of 12 results. Next

A133714 Row l=4 of array in A133713.

Original entry on oeis.org

1, 6, 25, 81, 226, 561, 1277, 2706, 5411, 10297, 18788, 33043, 56277, 93148, 150303, 237029, 366135, 554993, 826904, 1212695, 1752761, 2499432, 3519935, 4899801, 6747052, 9196983, 12417949, 16617932, 22052383, 29033069, 37938516
Offset: 0

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Programs

A133717 Row l=7 of array in A133713.

Original entry on oeis.org

1, 21, 266, 2541, 20097, 138103, 849514, 4771889, 24828755, 120944516, 556107055, 2429461391, 10137839293, 40585353434, 156451707633, 582555425669, 2100914443649, 7355423560191, 25050878785976, 83145222843357, 269368091719619
Offset: 0

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Programs

A133718 Column 3 of array in A133713.

Original entry on oeis.org

1, 13, 81, 325, 995, 2541, 5698, 11586, 21825, 38665, 65131, 105183, 163891, 247625, 364260, 523396, 736593, 1017621, 1382725, 1850905, 2444211, 3188053, 4111526, 5247750, 6634225, 8313201, 10332063, 12743731, 15607075
Offset: 2

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Programs

A133715 Row l=5 of array in A133713.

Original entry on oeis.org

1, 10, 65, 325, 1371, 5087, 17080, 52835, 152606, 415602, 1075410, 2660010, 6320476, 14485642, 32131580, 69181744, 144943566, 296136752, 591142760, 1154839554, 2211164332, 4154912452, 7671082770, 13930509344, 24906380837, 43880045952
Offset: 0

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Programs

A133716 Row l=6 of array in A133713.

Original entry on oeis.org

1, 15, 140, 995, 5901, 30569, 142375, 607700, 2410081, 8972559, 31608089, 106027825, 340416406, 1050541069, 3127340719, 9007681389, 25168555576, 68374424019, 180958790169, 467385754264, 1179927541924, 2915558734984, 7060185950979
Offset: 0

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Programs

A133719 Column 4 of array in A133713.

Original entry on oeis.org

1, 22, 226, 1371, 5901, 20097, 57813, 146427, 335742, 710677, 1408693, 2643004, 4732728, 8141238, 13524078, 21787914, 34162095, 52284504, 78303484, 114997729, 165916135, 235539711, 329467755, 454630605, 619531380, 834519231
Offset: 2

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Programs

A133720 Column 5 of array in A133713.

Original entry on oeis.org

1, 34, 561, 5087, 30569, 138103, 507360, 1594272, 4433484, 11176033, 25989535, 56493801, 115960208, 226569266, 424098592, 764503872, 1332959307, 2256042444, 3717882133, 5981238571, 9414651939, 14526981953, 22010865680, 32796846160
Offset: 2

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Programs

A133721 Triangle read by rows: T(m,n) = number of n-balanced and minimal labeled covers of a finite set of m unlabeled elements (m >= 1, 1 <= n <= m).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 6, 7, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 10, 1, 13, 1, 1, 1, 1, 1, 1, 1, 25, 7, 1, 1, 1, 1, 1, 1, 1, 15, 6, 3, 22, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 13, 1, 1, 1, 1, 1, 1, 1, 1, 21, 65, 81, 7, 34, 1, 1, 1, 1, 1, 1, 1, 1, 1, 10
Offset: 1

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Examples

			Triangle begins:
1
1 1
1 1 1
1 1 1 1
1 3 1 1 1
1 1 1 1 1 1
1 6 7 1 1 1 1
1 1 3 1 1 1 1 1
1 10 1 13 1 1 1 1 1
1 1 25 7 1 1 1 1 1 1
1 15 6 3 22 1 1 1 1 1 1
		

Crossrefs

Cf. A133709. Column n=2 is essentially A000217. Columns 3, 4, 5, 6 give A133722, A133723, A133724, A133733.

Programs

  • Maple
    A133721 := proc(m,n)
            l := ceil(m/n) ;
            c := n*ceil(m/n)-m ;
            A133713(l,c) ;
    end proc: # R. J. Mathar, Nov 23 2011
  • Mathematica
    A133713[l_, cl_] := Module[{g, k, s}, g = 1; For[k = 1, k <= cl+1, k++, s = Sum[Binomial[Binomial[l, k+1] + i-1, i]*t^(i*k), {i, 0, Ceiling[cl/k]}]; g = g*s]; g = Expand[g]; SeriesCoefficient[g, {t, 0, cl}]]; A133713[, 0] = 1; a[m, n_] := A133713[Ceiling[m/n], n*Ceiling[m/n] - m]; Table[a[m, n], {m, 1, 14}, {n, 1, m}] // Flatten (* Jean-François Alcover, Jan 20 2014, after R. J. Mathar *)

A133722 Column 3 of triangle in A133721.

Original entry on oeis.org

0, 0, 1, 1, 1, 1, 7, 3, 1, 25, 6, 1, 65, 10, 1, 140, 15, 1, 266, 21, 1, 462, 28, 1, 750, 36, 1, 1155, 45, 1, 1705, 55, 1, 2431, 66, 1, 3367, 78, 1, 4550, 91, 1, 6020, 105, 1, 7820, 120, 1, 9996, 136, 1, 12597, 153, 1, 15675
Offset: 1

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Programs

  • Maple
    A133722 := proc(n)
            A133721(n,3) ;
    end proc:
    seq(A133722(n),n=1..60) ; # R. J. Mathar, Nov 23 2011
  • Mathematica
    A133713[l_, cl_] := Module[{g, k, s}, g = 1; For[k = 1, k <= cl + 1, k++, s = Sum[Binomial[Binomial[l, k + 1] + i - 1, i]*t^(i*k), {i, 0, Ceiling[ cl/k]}]; g = g*s]; SeriesCoefficient[g, {t, 0, cl}]];
    a[m_, n_] := A133713[Ceiling[m/n], n*Ceiling[m/n] - m];
    Table[a[m, 3], {m, 1, 55}] (* Jean-François Alcover, Apr 03 2020, after R. J. Mathar *)

Formula

Conjectures from Colin Barker, Apr 03 2020: (Start)
G.f.: x^3*(1 + x + x^2 - 4*x^3 + 2*x^4 - 2*x^5 + 6*x^6 + x^8 - 4*x^9 + x^12) / ((1 - x)^5*(1 + x + x^2)^5).
a(n) = 5*a(n-3) - 10*a(n-6) + 10*a(n-9) - 5*a(n-12) + a(n-15) for n>14.
(End)

A133723 Column 4 of triangle in A133721.

Original entry on oeis.org

0, 0, 0, 1, 1, 1, 1, 1, 13, 7, 3, 1, 81, 25, 6, 1, 325, 65, 10, 1, 995, 140, 15, 1, 2541, 266, 21, 1, 5698, 462, 28, 1, 11586, 750, 36, 1, 21825, 1155, 45, 1, 38665, 1705, 55, 1, 65131, 2431, 66, 1, 105183, 3367, 78, 1, 163891, 4550, 91, 1
Offset: 1

Views

Author

N. J. A. Sloane, Dec 30 2007

Keywords

Programs

  • Maple
    A133723 := proc(n)
            A133721(n,4) ;
    end proc:
    seq(A133723(n),n=1..60) ; # R. J. Mathar, Nov 23 2011
  • Mathematica
    A133713[l_, cl_] := Module[{g, k, s}, g = 1; For[k = 1, k <= cl + 1, k++, s = Sum[Binomial[Binomial[l, k + 1] + i - 1, i]*t^(i*k), {i, 0, Ceiling[ cl/k]}]; g = g*s]; SeriesCoefficient[g, {t, 0, cl}]];
    a[m_, n_] := A133713[Ceiling[m/n], n*Ceiling[m/n] - m];
    Table[a[m, 4], {m, 1, 60}] (* Jean-François Alcover, Apr 03 2020, after R. J. Mathar *)
Showing 1-10 of 12 results. Next