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.

A202751 Number of n X n nonnegative integer arrays with each row and column increasing from zero by 0 or 1.

Original entry on oeis.org

1, 2, 8, 62, 924, 26394, 1442764, 150786848, 30114993376, 11489639088218, 8372083277093216, 11649087077771471438, 30947648445392475219812, 156963868041535457457609234, 1519762800266538697863301357568
Offset: 1

Views

Author

R. H. Hardin, Dec 23 2011

Keywords

Examples

			Some solutions for n=5:
  0 0 0 0 0    0 0 0 0 0    0 0 0 0 0    0 0 0 0 0
  0 0 0 1 1    0 0 0 1 1    0 0 0 1 1    0 0 0 0 0
  0 0 0 1 1    0 0 1 1 2    0 0 1 1 1    0 0 0 1 1
  0 1 1 1 1    0 0 1 2 3    0 1 1 2 2    0 0 1 2 2
  0 1 2 2 2    0 1 2 3 4    0 1 2 2 3    0 1 1 2 3
		

Crossrefs

Diagonal of A202756.

A202752 Number of n X 4 nonnegative integer arrays with each row and column increasing from zero by 0 or 1.

Original entry on oeis.org

1, 4, 17, 62, 184, 462, 1022, 2052, 3819, 6688, 11143, 17810, 27482, 41146, 60012, 85544, 119493, 163932, 221293, 294406, 386540, 501446, 643402, 817260, 1028495, 1283256, 1588419, 1951642, 2381422, 2887154, 3479192, 4168912, 4968777, 5892404
Offset: 1

Views

Author

R. H. Hardin, Dec 23 2011

Keywords

Comments

Column 4 of A202756.

Examples

			Some solutions for n=5:
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..0..0..1....0..0..0..1....0..0..0..0....0..0..1..1....0..0..0..0
..0..0..0..1....0..0..1..1....0..0..0..1....0..0..1..1....0..0..0..1
..0..1..1..1....0..0..1..2....0..0..0..1....0..1..2..2....0..0..1..2
..0..1..1..2....0..1..2..3....0..1..1..2....0..1..2..2....0..1..2..2
		

Crossrefs

Cf. A202756.

Formula

Empirical: a(n) = (1/360)*n^6 + (1/30)*n^5 + (5/72)*n^4 - (1/6)*n^3 + (77/180)*n^2 + (19/30)*n.
Conjectures from Colin Barker, Jun 01 2018: (Start)
G.f.: x*(1 - 3*x + 10*x^2 - 8*x^3 + 2*x^4) / (1 - x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.
(End)

A202753 Number of n X 5 nonnegative integer arrays with each row and column increasing from zero by 0 or 1.

Original entry on oeis.org

1, 5, 31, 184, 924, 3809, 13197, 39675, 106357, 259669, 586829, 1242946, 2491516, 4763097, 8738111, 15461061, 26494977, 44126629, 71634979, 113637500, 176531380, 269049265, 402952089, 593884703, 862423461, 1235348661, 1747178785
Offset: 1

Views

Author

R. H. Hardin, Dec 23 2011

Keywords

Comments

Column 5 of A202756.

Examples

			Some solutions for n=5:
..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..1..1..1..1....0..0..0..0..0....0..0..1..1..1....0..0..0..0..1
..0..1..1..1..2....0..0..0..1..1....0..1..1..1..1....0..0..0..0..1
..0..1..1..2..3....0..0..0..1..2....0..1..1..2..2....0..1..1..1..1
..0..1..2..3..4....0..0..1..1..2....0..1..2..2..2....0..1..1..2..2
		

Crossrefs

Cf. A202756.

Formula

Empirical: a(n) = (1/302400)*n^10 + (1/10080)*n^9 + (1/1008)*n^8 + (1/336)*n^7 - (67/14400)*n^6 + (7/480)*n^5 + (1021/6048)*n^4 - (145/1008)*n^3 + (10519/12600)*n^2 - (367/420)*n + 1.
Conjectures from Colin Barker, Jun 01 2018: (Start)
G.f.: x*(1 - 6*x + 31*x^2 - 47*x^3 + 110*x^4 - 162*x^5 + 140*x^6 - 79*x^7 + 31*x^8 - 8*x^9 + x^10) / (1 - x)^11.
a(n) = 11*a(n-1) - 55*a(n-2) + 165*a(n-3) - 330*a(n-4) + 462*a(n-5) - 462*a(n-6) + 330*a(n-7) - 165*a(n-8) + 55*a(n-9) - 11*a(n-10) + a(n-11) for n>11.
(End)

A202754 Number of n X 6 nonnegative integer arrays with each row and column increasing from zero by 0 or 1.

Original entry on oeis.org

1, 6, 51, 462, 3809, 26394, 150777, 721382, 2964632, 10720688, 34811491, 103179440, 282848319, 724794396, 1751160378, 4017593748, 8804203831, 18519925138, 37551252015, 73653037370, 140173677721, 259538952486, 468599962315
Offset: 1

Views

Author

R. H. Hardin, Dec 23 2011

Keywords

Comments

Column 6 of A202756.

Examples

			Some solutions for n=5:
  0 0 0 0 0 0   0 0 0 0 0 0   0 0 0 0 0 0   0 0 0 0 0 0
  0 0 1 1 1 1   0 0 0 1 1 1   0 0 0 0 0 0   0 0 0 1 1 1
  0 0 1 1 2 2   0 0 0 1 2 2   0 0 0 0 1 1   0 0 0 1 1 2
  0 0 1 1 2 2   0 0 0 1 2 3   0 0 1 1 1 2   0 0 1 2 2 3
  0 1 2 2 2 2   0 0 1 2 3 3   0 1 2 2 2 3   0 1 2 3 3 4
		

Programs

  • Maple
    seq((1/4572288000)*n^15 + (1/76204800)*n^14 + (41/130636800)*n^13 + (1/272160)*n^12 + (12631/653184000)*n^11 + (113/5443200)*n^10 + (2941/914457600)*n^9 + (661/381024)*n^8 + (1820467/326592000)*n^7 - (38281/10886400)*n^6 + (995867/16329600)*n^5 + (4181/68040)*n^4 - (253877/2646000)*n^3 + (233011/529200)*n^2 + (667/1260)*n, n=1..30); # Robert Israel, Jun 02 2019

Formula

Empirical: a(n) = (1/4572288000)*n^15 + (1/76204800)*n^14 + (41/130636800)*n^13 + (1/272160)*n^12 + (12631/653184000)*n^11 + (113/5443200)*n^10 + (2941/914457600)*n^9 + (661/381024)*n^8 + (1820467/326592000)*n^7 - (38281/10886400)*n^6 + (995867/16329600)*n^5 + (4181/68040)*n^4 - (253877/2646000)*n^3 + (233011/529200)*n^2 + (667/1260)*n.
Empirical formula verified (see link). - Robert Israel, Jun 02 2019

A202755 Number of nX7 nonnegative integer arrays with each row and column increasing from zero by 0 or 1.

Original entry on oeis.org

1, 7, 78, 1022, 13197, 150777, 1442764, 11408125, 75393424, 424992394, 2086954916, 9097630767, 35775808290, 128617512596, 427443971156, 1325376633243, 3864035126505, 10661515466643, 27995060608622, 70289431296342
Offset: 1

Views

Author

R. H. Hardin Dec 23 2011

Keywords

Comments

Column 7 of A202756

Examples

			Some solutions for n=5
..0..0..0..0..0..0..0....0..0..0..0..0..0..0....0..0..0..0..0..0..0
..0..0..0..0..1..1..1....0..0..0..0..0..0..1....0..0..0..0..0..0..1
..0..1..1..1..1..2..2....0..0..0..0..1..1..2....0..0..0..1..1..1..2
..0..1..1..2..2..3..3....0..0..1..1..1..2..3....0..0..1..1..1..1..2
..0..1..1..2..2..3..4....0..1..1..2..2..3..3....0..0..1..2..2..2..2
		

Formula

Empirical: a(n) = (1/1520925880320000)*n^21 + (1/14485008384000)*n^20 + (17/5431878144000)*n^19 + (41/517321728000)*n^18 + (10847/9053130240000)*n^17 + (73/6897623040)*n^16 + (3646499/76046294016000)*n^15 + (340729/3621252096000)*n^14 + (186024683/217275125760000)*n^13 + (282751/26873856000)*n^12 + (25808261/724250419200)*n^11 + (2895163/86220288000)*n^10 + (493582091273/760462940160000)*n^9 + (2226946937/1034643456000)*n^8 - (263782703/2715939072000)*n^7 + (3455599541/129330432000)*n^6 - (31330211789/754427520000)*n^5 + (2559599737/7185024000)*n^4 - (3245092381/7334712000)*n^3 + (7079701/6350400)*n^2 - (28181/27720)*n + 1
Showing 1-5 of 5 results.