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

A200880 Number of 0..2 arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors.

Original entry on oeis.org

22, 51, 121, 292, 704, 1691, 4059, 9749, 23422, 56268, 135166, 324692, 779977, 1873673, 4500958, 10812237, 25973244, 62393157, 149881402, 360046432, 864906711, 2077686532, 4991036946, 11989513056, 28801314179, 69186771332
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Column 2 of A200886.

Examples

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

Formula

Empirical: a(n) = 3*a(n-1) -3*a(n-2) +4*a(n-3) -a(n-4) +a(n-5).
Empirical g.f.: x*(22 - 15*x + 34*x^2 - 6*x^3 + 9*x^4) / (1 - 3*x + 3*x^2 - 4*x^3 + x^4 - x^5). - Colin Barker, Oct 16 2017

A200881 Number of 0..3 arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors.

Original entry on oeis.org

50, 144, 422, 1268, 3823, 11472, 34350, 102896, 308419, 924532, 2771101, 8305373, 24892609, 74608516, 223618304, 670231838, 2008825312, 6020872062, 18045827096, 54087163859, 162110668160, 485879938474, 1456284886944, 4364793695063
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Column 3 of A200886.

Examples

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

Formula

Empirical: a(n) = 4*a(n-1) -6*a(n-2) +10*a(n-3) -5*a(n-4) +6*a(n-5) -a(n-6) +a(n-7).
Empirical g.f.: x*(50 - 56*x + 146*x^2 - 56*x^3 + 93*x^4 - 12*x^5 + 16*x^6) / (1 - 4*x + 6*x^2 - 10*x^3 + 5*x^4 - 6*x^5 + x^6 - x^7). - Colin Barker, Oct 16 2017

A200882 Number of 0..4 arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors.

Original entry on oeis.org

95, 325, 1121, 3985, 14288, 50995, 181336, 644721, 2294193, 8166441, 29066618, 103444256, 368138471, 1310164527, 4662787112, 16594519920, 59058487061, 210183969235, 748026706926, 2662163892493, 9474416502527, 33718645047381
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Column 4 of A200886.

Examples

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

Formula

Empirical: a(n) = 5*a(n-1) -10*a(n-2) +20*a(n-3) -15*a(n-4) +21*a(n-5) -7*a(n-6) +8*a(n-7) -a(n-8) +a(n-9).
Empirical g.f.: x*(95 - 150*x + 446*x^2 - 270*x^3 + 498*x^4 - 135*x^5 + 196*x^6 - 20*x^7 + 25*x^8) / (1 - 5*x + 10*x^2 - 20*x^3 + 15*x^4 - 21*x^5 + 7*x^6 - 8*x^7 + x^8 - x^9). - Colin Barker, Oct 16 2017

A200883 Number of 0..5 arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors.

Original entry on oeis.org

161, 636, 2507, 10213, 42182, 173606, 710976, 2908797, 11911516, 48807427, 199987737, 819315100, 3356387171, 13749952752, 56330082115, 230771042950, 945410224602, 3873094298871, 15867039092263, 65003096433432
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Column 5 of A200886.

Examples

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

Formula

Empirical: a(n) = 6*a(n-1) -15*a(n-2) +35*a(n-3) -35*a(n-4) +56*a(n-5) -28*a(n-6) +36*a(n-7) -9*a(n-8) +10*a(n-9) -a(n-10) +a(n-11).
Empirical g.f.: x*(161 - 330*x + 1106*x^2 - 924*x^3 + 1884*x^4 - 792*x^5 + 1252*x^6 - 264*x^7 + 355*x^8 - 30*x^9 + 36*x^10) / (1 - 6*x + 15*x^2 - 35*x^3 + 35*x^4 - 56*x^5 + 28*x^6 - 36*x^7 + 9*x^8 - 10*x^9 + x^10 - x^11). - Colin Barker, Oct 16 2017

A200884 Number of 0..6 arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors.

Original entry on oeis.org

252, 1127, 4977, 22736, 105813, 491533, 2269938, 10462235, 48259083, 222798408, 1028746629, 4749274209, 21922813539, 101196577809, 467142348798, 2156444661242, 9954648966159, 45952741121083, 212127214776309
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Column 6 of A200886.

Examples

			Some solutions for n=3
..6....1....2....1....1....4....0....2....2....5....3....3....4....1....4....5
..6....1....2....1....3....4....1....1....5....2....3....3....0....3....0....6
..5....0....5....5....4....4....2....1....5....0....2....1....2....5....1....6
..2....2....5....5....4....2....4....5....0....3....2....1....3....5....6....5
..6....3....6....3....1....3....4....6....5....4....5....5....6....1....6....4
		

Formula

Empirical: a(n) = 7*a(n-1) -21*a(n-2) +56*a(n-3) -70*a(n-4) +126*a(n-5) -84*a(n-6) +120*a(n-7) -45*a(n-8) +55*a(n-9) -11*a(n-10) +12*a(n-11) -a(n-12) +a(n-13).
Empirical g.f.: x*(252 - 637*x + 2380*x^2 - 2548*x^3 + 5706*x^4 - 3276*x^5 + 5620*x^6 - 1820*x^7 + 2630*x^8 - 455*x^9 + 582*x^10 - 42*x^11 + 49*x^12) / (1 - 7*x + 21*x^2 - 56*x^3 + 70*x^4 - 126*x^5 + 84*x^6 - 120*x^7 + 45*x^8 - 55*x^9 + 11*x^10 - 12*x^11 + x^12 - x^13). - Colin Barker, Oct 16 2017

A200885 Number of 0..7 arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors.

Original entry on oeis.org

372, 1856, 9052, 45648, 235538, 1215616, 6233356, 31868448, 163014678, 834763824, 4276077566, 21900661172, 112149148911, 574278200480, 2940790043388, 15059692639376, 77120252989206, 394927990211792, 2022395235481866
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Column 7 of A200886.

Examples

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

Formula

Empirical: a(n) = 8*a(n-1) -28*a(n-2) +84*a(n-3) -126*a(n-4) +252*a(n-5) -210*a(n-6) +330*a(n-7) -165*a(n-8) +220*a(n-9) -66*a(n-10) +78*a(n-11) -13*a(n-12) +14*a(n-13) -a(n-14) +a(n-15).
Empirical g.f.: x*(372 - 1120*x + 4620*x^2 - 6048*x^3 + 14778*x^4 - 10800*x^5 + 20020*x^6 - 8800*x^7 + 13630*x^8 - 3600*x^9 + 4902*x^10 - 720*x^11 + 889*x^12 - 56*x^13 + 64*x^14) / (1 - 8*x + 28*x^2 - 84*x^3 + 126*x^4 - 252*x^5 + 210*x^6 - 330*x^7 + 165*x^8 - 220*x^9 + 66*x^10 - 78*x^11 + 13*x^12 - 14*x^13 + x^14 - x^15). - Colin Barker, Oct 16 2017

A200887 Number of 0..n arrays x(0..3) of 4 elements without any interior element greater than both neighbors.

Original entry on oeis.org

12, 51, 144, 325, 636, 1127, 1856, 2889, 4300, 6171, 8592, 11661, 15484, 20175, 25856, 32657, 40716, 50179, 61200, 73941, 88572, 105271, 124224, 145625, 169676, 196587, 226576, 259869, 296700, 337311, 381952, 430881, 484364, 542675, 606096, 674917
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Row 2 of A200886.

Examples

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

Formula

Empirical: a(n) = (1/3)*n^4 + (7/3)*n^3 + (14/3)*n^2 + (11/3)*n + 1.
Conjectures from Colin Barker, Oct 16 2017: (Start)
G.f.: x*(12 - 9*x + 9*x^2 - 5*x^3 + x^4) / (1 - x)^5.
a(n) = (1+n)^2 * (3+5*n+n^2) / 3.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>5.
(End)

A200888 Number of 0..n arrays x(0..4) of 5 elements without any interior element greater than both neighbors.

Original entry on oeis.org

21, 121, 422, 1121, 2507, 4977, 9052, 15393, 24817, 38313, 57058, 82433, 116039, 159713, 215544, 285889, 373389, 480985, 611934, 769825, 958595, 1182545, 1446356, 1755105, 2114281, 2529801, 3008026, 3555777, 4180351, 4889537, 5691632, 6595457
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Row 3 of A200886.

Examples

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

Formula

Empirical: a(n) = (2/15)*n^5 + (11/6)*n^4 + (35/6)*n^3 + (23/3)*n^2 + (68/15)*n + 1.
Conjectures from Colin Barker, Oct 16 2017: (Start)
G.f.: x*(21 - 5*x + 11*x^2 - 16*x^3 + 6*x^4 - x^5) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)

A200889 Number of 0..n arrays x(0..5) of 6 elements without any interior element greater than both neighbors.

Original entry on oeis.org

37, 292, 1268, 3985, 10213, 22736, 45648, 84681, 147565, 244420, 388180, 595049, 884989, 1282240, 1815872, 2520369, 3436245, 4610692, 6098260, 7961569, 10272053, 13110736, 16569040, 20749625, 25767261, 31749732, 38838772, 47191033, 56979085
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Row 4 of A200886.

Examples

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

Formula

Empirical: a(n) = (2/45)*n^6 + (19/15)*n^5 + (217/36)*n^4 + (71/6)*n^3 + (2057/180)*n^2 + (27/5)*n + 1.
Conjectures from Colin Barker, Oct 16 2017: (Start)
G.f.: x*(37 + 33*x + x^2 - 54*x^3 + 21*x^4 - 7*x^5 + x^6) / (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)

A200890 Number of 0..n arrays x(0..6) of 7 elements without any interior element greater than both neighbors.

Original entry on oeis.org

65, 704, 3823, 14288, 42182, 105813, 235538, 478467, 904111, 1611038, 2734601, 4455802, 7011356, 10705019, 15920244, 23134229, 32933421, 46030540, 63283187, 85714100, 114533122, 151160945, 197254694, 254735415, 325817531, 413040330
Offset: 1

Views

Author

R. H. Hardin, Nov 23 2011

Keywords

Comments

Row 5 of A200886.

Examples

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

Formula

Empirical: a(n) = (4/315)*n^7 + (7/9)*n^6 + (241/45)*n^5 + (1067/72)*n^4 + (3757/180)*n^3 + (1145/72)*n^2 + (2629/420)*n + 1.
Conjectures from Colin Barker, Oct 16 2017: (Start)
G.f.: x*(65 + 184*x + 11*x^2 - 224*x^3 + 48*x^4 - 27*x^5 + 8*x^6 - x^7) / (1 - x)^8.
a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>8.
(End)
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