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.

A221140 Second-order spt function.

Original entry on oeis.org

0, 1, 5, 15, 35, 75, 140, 259, 435, 735, 1155, 1841, 2765, 4200, 6125, 8975, 12731, 18179, 25235, 35180, 48055, 65681, 88299, 118895, 157690, 209230, 274510, 359779, 466970, 605740, 778860, 1000462, 1276044, 1624845, 2056355, 2598855, 3265851, 4097763, 5117350
Offset: 1

Views

Author

N. J. A. Sloane, Jan 02 2013

Keywords

Crossrefs

Programs

  • Mathematica
    om[2, p_List] := Module[{pu, m, f}, pu = Union[p]; m = Length[pu]; f[j_] := Count[p, pu[[j]]]; Binomial[f[1] + 1, 3] + f[1] Sum[Binomial[f[j] + 1, 2], {j, 2, m}]];
    spt[2, n_] := Sum[om[2, p], {p, IntegerPartitions[n]}];
    Table[spt[2, n], {n, 1, 29}] (* Jean-François Alcover, Mar 30 2020 *)

Extensions

More terms from Jean-François Alcover, Mar 30 2020

A221141 Third-order spt function.

Original entry on oeis.org

0, 0, 1, 7, 28, 85, 217, 497, 1036, 2044, 3787, 6797, 11648, 19558, 31703, 50645, 78674, 120932, 181664, 270600, 395682, 574329, 820834, 1166109, 1634668, 2279242, 3142903, 4312063, 5859616, 7927745, 10635129, 14209328, 18846744, 24900807, 32688145, 42761047
Offset: 1

Views

Author

N. J. A. Sloane, Jan 02 2013

Keywords

Crossrefs

Programs

  • Mathematica
    om[3, p_List] := Module[{pu, m, f}, pu = Union[p]; m = Length[pu]; f[j_] := Count[p, pu[[j]]]; Binomial[f[1] + 2, 5] + Binomial[f[1] + 1, 3] Sum[ Binomial[f[j] + 1, 2], {j, 2, m}] + f[1] Sum[Binomial[f[j] + 2, 4], {j, 2, m}] + f[1] Sum[Binomial[f[j] + 1, 2] Binomial[f[k] + 1, 2], {j, 2, m}, {k, j + 1, m}]];
    spt[3, n_] := Sum[om[3, p], {p, IntegerPartitions[n]}];
    Table[spt[3, n], {n, 1, 29}] (* Jean-François Alcover, Mar 30 2020 *)

Extensions

More terms from Jean-François Alcover, Mar 30 2020

A221144 Sixth-order spt function.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 13, 91, 456, 1834, 6293, 19125, 52781, 134643, 321622, 726650, 1564696, 3231635, 6432859, 12395504, 23195905, 42287433, 75274166, 131143033, 223982780, 375713010, 619712403, 1006599177, 1611563058, 2546148075, 3972522337, 6126699846, 9345436668
Offset: 1

Views

Author

N. J. A. Sloane, Jan 02 2013

Keywords

Crossrefs

Extensions

More terms from Jinyuan Wang, Aug 08 2021

A221143 Fifth-order spt function.

Original entry on oeis.org

0, 0, 0, 0, 1, 11, 66, 287, 1013, 3081, 8372, 20824, 48192, 105117, 217945, 433017, 828346, 1534271, 2759132, 4837638, 8283014, 13894554, 22856717, 36968045, 58818578, 92258215, 142699970, 218041302, 329162610, 491683915, 726746512, 1064266795, 1544134041
Offset: 1

Views

Author

N. J. A. Sloane, Jan 02 2013

Keywords

Crossrefs

Extensions

More terms from Jinyuan Wang, Aug 08 2021

A211977 Triangle read by rows, T(n,k) = spt_k(n), in which column k lists the k-th order spt-function (without the first k-1 zeros), n >= 1, k >= 1.

Original entry on oeis.org

1, 3, 1, 5, 5, 1, 10, 15, 7, 1, 14, 35, 28, 9, 1, 26, 75, 85, 45, 11, 1, 35, 140, 217, 166, 66, 13, 1, 57, 259, 497, 505, 287, 91
Offset: 1

Views

Author

Omar E. Pol, Jan 03 2013

Keywords

Comments

The triangle arises from a table due to F. G. Garvan (See the Garvan's paper, page 19).

Examples

			Triangle begins:
   1;
   3,   1;
   5,   5,   1;
  10,  15,   7,   1;
  14,  35,  28,   9,   1;
  26,  75,  85,  45,  11,   1;
  35, 140, 217, 166,  66,  13,  1;
  ...
		

Crossrefs

Showing 1-5 of 5 results.