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 1-6 of 6 results.

A188778 Number of 3-turn bishop's tours on an n X n board summed over all starting positions.

Original entry on oeis.org

0, 0, 28, 152, 488, 1192, 2468, 4560, 7760, 12400, 18860, 27560, 38968, 53592, 71988, 94752, 122528, 156000, 195900, 243000, 298120, 362120, 435908, 520432, 616688, 725712, 848588, 986440, 1140440, 1311800, 1501780, 1711680, 1942848, 2196672
Offset: 1

Views

Author

R. H. Hardin Apr 10 2011

Keywords

Comments

Row 3 of A188777

Examples

			Some solutions for 4X4
..0..0..0..0....0..0..0..1....1..0..0..0....0..0..0..0....0..0..2..0
..1..0..0..0....0..0..0..0....0..3..0..0....3..0..0..0....0..0..0..3
..0..3..0..0....0..2..0..0....0..0..0..0....0..1..0..0....1..0..0..0
..0..0..2..0....0..0..3..0....0..0..0..2....0..0..2..0....0..0..0..0
		

Formula

Empirical: a(n) = 4*a(n-1) -5*a(n-2) +5*a(n-4) -4*a(n-5) +a(n-6)
Contribution from Vaclav Kotesovec, Sep 01 2012: (Start)
Empirical: G.f.: 4*x^3*(7 + 10*x + 5*x^2)/((1-x)^5*(1+x))
Empirical: a(n) = 1/4 - 10*n/3 + 23*n^2/3 - 20*n^3/3 + 11*n^4/6 - (-1)^n/4
(End)

A188779 Number of 4-turn bishop's tours on an n X n board summed over all starting positions.

Original entry on oeis.org

0, 0, 24, 328, 1720, 5816, 15424, 34736, 69776, 128528, 221448, 361528, 564872, 850696, 1241968, 1765344, 2451872, 3336864, 4460664, 5868456, 7611096, 9744856, 12332320, 15442064, 19149616, 23537072, 28694120, 34717592, 41712552, 49791784
Offset: 1

Views

Author

R. H. Hardin Apr 10 2011

Keywords

Comments

Row 4 of A188777

Examples

			Some solutions for 4X4
..0..0..0..1....0..0..0..0....0..0..1..0....0..0..0..0....0..4..0..1
..0..0..3..0....1..0..0..0....0..4..0..2....0..4..0..2....3..0..0..0
..0..4..0..0....0..2..0..4....0..0..3..0....0..0..3..0....0..2..0..0
..2..0..0..0....0..0..3..0....0..0..0..0....0..1..0..0....0..0..0..0
		

Formula

Empirical: a(n) = 4*a(n-1) -4*a(n-2) -4*a(n-3) +10*a(n-4) -4*a(n-5) -4*a(n-6) +4*a(n-7) -a(n-8)
Contribution from Vaclav Kotesovec, Sep 01 2012: (Start)
Empirical: G.f.: 8*x^3*(3 + 29*x + 63*x^2 + 43*x^3 + 14*x^4)/((1-x)^6*(1+x)^2)
Empirical: a(n) = -2 + 257*n/15 - 109*n^2/3 + 106*n^3/3 - 47*n^4/3 + 38*n^5/15 + (-1)^n*(2-n)
(End)

A188780 Number of 5-turn bishop's tours on an n X n board summed over all starting positions.

Original entry on oeis.org

0, 0, 8, 584, 5464, 26360, 91120, 252720, 603696, 1288592, 2525400, 4620728, 7998984, 13219528, 21014336, 32306400, 48256608, 70282656, 100115880, 139819944, 191858360, 259112216, 344959120, 453289232, 588596368, 755991600
Offset: 1

Views

Author

R. H. Hardin Apr 10 2011

Keywords

Comments

Row 5 of A188777

Examples

			Some solutions for 4X4
..0..5..0..0....0..5..0..0....0..5..0..0....0..0..2..0....0..4..0..0
..1..0..4..0....0..0..1..0....0..0..3..0....0..5..0..3....0..0..3..0
..0..3..0..0....0..2..0..4....0..2..0..4....1..0..4..0....0..2..0..5
..0..0..2..0....0..0..3..0....1..0..0..0....0..0..0..0....0..0..1..0
		

Formula

Empirical: a(n) = 4*a(n-1) -3*a(n-2) -8*a(n-3) +14*a(n-4) -14*a(n-6) +8*a(n-7) +3*a(n-8) -4*a(n-9) +a(n-10)
Contribution from Vaclav Kotesovec, Sep 01 2012: (Start)
Empirical: G.f.: 8*x^3*(1 + 69*x + 394*x^2 + 790*x^3 + 829*x^4 + 357*x^5 + 84*x^6)/((1-x)^7*(1+x)^3)
Empirical: a(n) = 51/4 - 913*n/10 + 69203*n^2/360 - 602*n^3/3 + 1007*n^4/9 - 473*n^5/15 + 631*n^6/180 + (-1)^n*(-51/4 + 25*n/2 - 23*n^2/8)
(End)

A188781 Number of 6-turn bishop's tours on an n X n board summed over all starting positions.

Original entry on oeis.org

0, 0, 0, 840, 15824, 112680, 516160, 1778608, 5082912, 12622640, 28225472, 58013112, 111476080, 202472856, 350897664, 584067552, 939135552, 1464903648, 2225144448, 3300867240, 4794722064, 6833735304, 9574980800, 13208790672
Offset: 1

Views

Author

R. H. Hardin, Apr 10 2011

Keywords

Comments

Row 6 of A188777.

Examples

			Some solutions for 4 X 4
..0..0..4..0....0..2..0..6....0..4..0..1....0..3..0..0....0..5..0..3
..0..3..0..1....1..0..4..0....5..0..2..0....2..0..4..0....6..0..4..0
..5..0..2..0....0..5..0..3....0..0..0..3....0..1..0..5....0..2..0..0
..0..6..0..0....0..0..0..0....0..0..6..0....0..0..6..0....1..0..0..0
		

Crossrefs

Cf. A188777.

Formula

Empirical: a(n) = 4*a(n-1) -2*a(n-2) -12*a(n-3) +17*a(n-4) +8*a(n-5) -28*a(n-6) +8*a(n-7) +17*a(n-8) -12*a(n-9) -2*a(n-10) +4*a(n-11) -a(n-12).
From Vaclav Kotesovec, Sep 01 2012: (Start)
Empirical: G.f.: 8*x^4*(105 + 1558*x + 6383*x^2 + 13396*x^3 + 14367*x^4 + 9654*x^5 + 2937*x^6 + 528*x^7)/((1-x)^8*(1+x)^4).
Empirical: a(n) = -297/4 + 13961*n/28 - 32551*n^2/30 + 54158*n^3/45 - 4625*n^4/6 + 5189*n^5/18 - 872*n^6/15 + 1529*n^7/315 + (-1)^n*(297/4 - 439*n/4 + 99*n^2/2 - 7*n^3).
(End)

A188782 Number of 7-turn bishop's tours on an n X n board summed over all starting positions.

Original entry on oeis.org

0, 0, 0, 784, 40496, 451104, 2803552, 12139552, 41792672, 121269248, 310362944, 718151344, 1534460624, 3067048224, 5801302304, 10464095808, 18125622336, 30299632896, 49104515712, 77410664016, 119081302128, 179178580768
Offset: 1

Views

Author

R. H. Hardin, Apr 10 2011

Keywords

Comments

Row 7 of A188777.

Examples

			Some solutions for 4 X 4
..0..4..0..2....0..3..0..0....4..0..0..0....0..0..1..0....0..0..3..0
..7..0..3..0....4..0..2..0....0..3..0..7....0..5..0..2....0..1..0..4
..0..1..0..5....0..6..0..1....2..0..6..0....4..0..6..0....2..0..6..0
..0..0..6..0....7..0..5..0....0..1..0..5....0..3..0..7....0..5..0..7
		

Crossrefs

Cf. A188777.

Formula

Contribution from Vaclav Kotesovec, Sep 01 2012: (Start)
Empirical: Recurrence: a(n) = a(n-14) - 4*a(n-13) + a(n-12) + 16*a(n-11) - 19*a(n-10) - 20*a(n-9) + 45*a(n-8) - 45*a(n-6) + 20*a(n-5) + 19*a(n-4) - 16*a(n-3) - a(n-2) + 4*a(n-1).
Empirical: G.f.: 16*x^4*(49 + 2335*x + 18119*x^2 + 65761*x^3 + 125593*x^4 + 154411*x^5 + 109333*x^6 + 52763*x^7 + 12090*x^8 + 1722*x^9)/((1-x)^9*(1+x)^5).
Empirical: a(n) = 6421/16 - 581677*n/210 + 2022619*n^2/315 - 340262*n^3/45 + 1915471*n^4/360 - 106466*n^5/45 + 29363*n^6/45 - 31916*n^7/315 + 16943*n^8/2520 + (-1)^n*(-6421/16 + 1645*n/2 - 557*n^2 + 155*n^3 - 123*n^4/8).
(End)

A188783 Number of 8-turn bishop's tours on an n X n board summed over all starting positions.

Original entry on oeis.org

0, 0, 0, 384, 88264, 1665344, 14497784, 80088992, 335122320, 1142391712, 3358831216, 8772323808, 20882774744, 46000760736, 95075730152, 186010966464, 347367851808, 622687135680, 1077266143968, 1805545001664, 2942598571752
Offset: 1

Views

Author

R. H. Hardin Apr 10 2011

Keywords

Comments

Row 8 of A188777

Examples

			Some solutions for 4X4
..0..3..0..8....4..0..7..0....4..0..8..0....0..5..0..1....0..8..0..1
..6..0..2..0....0..6..0..1....0..2..0..7....6..0..3..0....5..0..3..0
..0..7..0..4....8..0..3..0....1..0..5..0....0..8..0..4....0..4..0..7
..1..0..5..0....0..2..0..5....0..6..0..3....2..0..7..0....2..0..6..0
		

Formula

From Vaclav Kotesovec, Sep 01 2012: (Start)
Empirical: Recurrence: a(n) = a(n-17) - 5*a(n-16) + 4*a(n-15) + 20*a(n-14) - 40*a(n-13) - 16*a(n-12) + 100*a(n-11) - 44*a(n-10) - 110*a(n-9) + 110*a(n-8) + 44*a(n-7) - 100*a(n-6) + 16*a(n-5) + 40*a(n-4) - 20*a(n-3) - 4*a(n-2) + 5*a(n-1)
Empirical: G.f.: 8*x^4*(48 + 10841*x + 164036*x^2 + 980511*x^3 + 2981932*x^4 + 5786766*x^5 + 6924788*x^6 + 5849090*x^7 + 3007252*x^8 + 1111577*x^9 + 201048*x^10 + 23391*x^11)/((1-x)^10*(1+x)^6)
Empirical: a(n) = -31395/16 + 31519*n/2 - 50452903*n^2/1260 + 13521503*n^3/270 - 4517641*n^4/120 + 224087*n^5/12 - 93658*n^6/15 + 60857*n^7/45 - 428119*n^8/2520 + 503*n^9/54 + (-1)^n*(31395/16 - 55203*n/10 + 20473*n^2/4 - 4275*n^3/2 + 3349*n^4/8 - 629*n^5/20)
(End)
Showing 1-6 of 6 results.