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 11 results. Next

A269613 Number of length-n 0..2 arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

3, 9, 27, 78, 222, 624, 1740, 4824, 13320, 36672, 100752, 276384, 757344, 2073600, 5674176, 15520128, 42437760, 116014080, 317100288, 866621952, 2368230912, 6471278592, 17682164736, 48313178112, 132003268608, 360658059264
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Comments

Column 2 of A269619.

Examples

			Some solutions for n=8:
..1. .1. .0. .0. .0. .1. .1. .1. .2. .2. .2. .1. .1. .1. .0. .1
..2. .1. .0. .0. .2. .2. .1. .2. .1. .0. .0. .0. .1. .2. .2. .0
..2. .0. .0. .1. .2. .1. .0. .1. .2. .0. .2. .2. .2. .1. .0. .1
..2. .1. .1. .2. .2. .1. .1. .1. .0. .2. .1. .1. .1. .2. .0. .0
..2. .2. .2. .0. .1. .0. .1. .0. .1. .0. .1. .1. .0. .0. .1. .0
..2. .0. .2. .2. .2. .0. .1. .1. .1. .0. .2. .2. .1. .2. .2. .1
..1. .0. .1. .0. .1. .2. .0. .1. .1. .1. .0. .0. .1. .1. .2. .2
..1. .0. .1. .2. .0. .1. .0. .1. .1. .2. .2. .1. .0. .2. .1. .1
		

Crossrefs

Cf. A269619.

Formula

Empirical: a(n) = 4*a(n-1) - 2*a(n-2) - 4*a(n-3).
Conjectures from Colin Barker, Mar 21 2018: (Start)
G.f.: 3*x*(1 - x - x^2) / ((1 - 2*x)*(1 - 2*x - 2*x^2)).
a(n) = (-3*2^n + (3-2*sqrt(3))*(1-sqrt(3))^n + (1+sqrt(3))^n*(3+2*sqrt(3))) / 4.
(End)

A269612 Number of length-n 0..n arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

2, 9, 64, 612, 7440, 110099, 1923796, 38800210, 887591878, 22714070251, 643030722208, 19954247152834, 673552866591198, 24570545121277999, 963253518328620796, 40387590591059009524, 1803427358679591518028
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Comments

Diagonal of A269619.

Examples

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

Crossrefs

Cf. A269619.

A269614 Number of length-n 0..3 arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

4, 16, 64, 249, 954, 3611, 13544, 50442, 186822, 688899, 2531406, 9275757, 33912330, 123759252, 450985950, 1641487455, 5969001906, 21688869249, 78760649178, 285872602590, 1037218320720, 3762161399673, 13642773106086, 49463937282915
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

			Some solutions for n=8:
..0. .3. .2. .3. .1. .0. .0. .0. .2. .2. .2. .3. .2. .2. .2. .3
..3. .3. .1. .3. .3. .2. .2. .2. .0. .3. .1. .1. .1. .3. .2. .0
..3. .0. .3. .2. .2. .1. .0. .3. .1. .3. .3. .3. .2. .0. .2. .0
..2. .3. .2. .2. .1. .3. .0. .3. .0. .1. .2. .2. .1. .0. .1. .2
..3. .2. .3. .2. .0. .2. .1. .0. .1. .0. .0. .3. .3. .1. .3. .0
..1. .2. .3. .1. .0. .3. .2. .3. .3. .3. .0. .2. .1. .2. .1. .2
..0. .1. .0. .3. .3. .3. .0. .2. .0. .3. .2. .3. .2. .0. .0. .0
..3. .0. .2. .0. .1. .1. .2. .3. .2. .1. .3. .3. .1. .0. .3. .1
		

Crossrefs

Column 3 of A269619.

Formula

Empirical: a(n) = 12*a(n-1) - 51*a(n-2) + 81*a(n-3) - 3*a(n-4) - 63*a(n-5) - 24*a(n-6) - 9*a(n-7).
Empirical g.f.: x*(4 - 32*x + 76*x^2 - 27*x^3 - 54*x^4 - 22*x^5 - 7*x^6) / ((1 - 3*x)*(1 - 9*x + 24*x^2 - 9*x^3 - 24*x^4 - 9*x^5 - 3*x^6)). - Colin Barker, Jan 25 2019

A269615 Number of length-n 0..4 arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

5, 25, 125, 612, 2956, 14125, 66925, 314935, 1473779, 6865098, 31856590, 147352985, 679742085, 3128486473, 14370696813, 65902020548, 301787376436, 1380297559417, 6306497302225, 28787967919963, 131309246498679, 598532215284482
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Column 4 of A269619.

Formula

Empirical: a(n) = 16*a(n-1) - 93*a(n-2) + 220*a(n-3) - 115*a(n-4) - 168*a(n-5) - 44*a(n-6) - 16*a(n-7).
Empirical g.f.: x*(5 - 55*x + 190*x^2 - 163*x^3 - 136*x^4 - 40*x^5 - 12*x^6) / ((1 - 4*x)*(1 - 12*x + 45*x^2 - 40*x^3 - 45*x^4 - 12*x^5 - 4*x^6)). - Colin Barker, Jan 25 2019

A269616 Number of length-n 0..5 arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

6, 36, 216, 1275, 7440, 43013, 246798, 1407232, 7982022, 45074673, 253574688, 1421878274, 7950451524, 44345786735, 246818403470, 1371136321437, 7604288654552, 42110933628975, 232895831580810, 1286536158378699
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Comments

Column 5 of A269619.

Examples

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

Crossrefs

Cf. A269619.

Formula

Empirical: a(n) = 35*a(n-1) -519*a(n-2) +4195*a(n-3) -19640*a(n-4) +51000*a(n-5) -56851*a(n-6) -16105*a(n-7) +50448*a(n-8) +35280*a(n-9) +12993*a(n-10) +3195*a(n-11) +444*a(n-12) +30*a(n-13)

A269617 Number of length-n 0..6 arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

7, 49, 343, 2370, 16218, 110099, 742487, 4979260, 33232924, 220896016, 1463045800, 9659912834, 63605763734, 417796855262, 2738396932202, 17913923467256, 116986307701928, 762789970679730, 4966685787053850, 32298201110078751
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Comments

Column 6 of A269619.

Examples

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

Crossrefs

Cf. A269619.

Formula

Empirical: a(n) = 48*a(n-1) -1001*a(n-2) +11802*a(n-3) -85449*a(n-4) +383292*a(n-5) -1000148*a(n-6) +1185936*a(n-7) +212633*a(n-8) -1064856*a(n-9) -732405*a(n-10) -264438*a(n-11) -65802*a(n-12) -10656*a(n-13) -1071*a(n-14) -54*a(n-15)

A269618 Number of length-n 0..7 arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

8, 64, 512, 4053, 31822, 248143, 1923796, 14840928, 113998742, 872397577, 6654286340, 50608816911, 383908730032, 2905532655620, 21944295375268, 165426094919204, 1244944198391978, 9354631892435631, 70193014149728040
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Comments

Column 7 of A269619.

Examples

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

Crossrefs

Cf. A269619.

Formula

Empirical: a(n) = 63*a(n-1) -1756*a(n-2) +28364*a(n-3) -291578*a(n-4) +1965390*a(n-5) -8566706*a(n-6) +22451548*a(n-7) -27837343*a(n-8) -2892449*a(n-9) +25243250*a(n-10) +17146752*a(n-11) +6127748*a(n-12) +1523522*a(n-13) +264748*a(n-14) +31542*a(n-15) +2437*a(n-16) +91*a(n-17)

A269620 Number of length-4 0..n arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

15, 78, 249, 612, 1275, 2370, 4053, 6504, 9927, 14550, 20625, 28428, 38259, 50442, 65325, 83280, 104703, 130014, 159657, 194100, 233835, 279378, 331269, 390072, 456375, 530790, 613953, 706524, 809187, 922650, 1047645, 1184928, 1335279
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

			Some solutions for n=8:
..2. .5. .6. .8. .5. .2. .1. .4. .1. .5. .5. .6. .0. .5. .7. .2
..2. .7. .2. .7. .2. .2. .0. .6. .0. .1. .6. .0. .3. .6. .1. .5
..6. .5. .7. .0. .2. .3. .6. .7. .0. .5. .1. .2. .5. .2. .7. .2
..3. .2. .6. .0. .5. .8. .0. .6. .7. .6. .2. .2. .4. .4. .2. .4
		

Crossrefs

Row 4 of A269619.

Formula

Empirical: a(n) = n^4 + 4*n^3 + 5*n^2 + 5*n.
Conjectures from Colin Barker, Jan 25 2019: (Start)
G.f.: 3*x*(5 + x + 3*x^2 - x^3) / (1 - x)^5.
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)

A269621 Number of length-5 0..n arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

28, 222, 954, 2956, 7440, 16218, 31822, 57624, 97956, 158230, 245058, 366372, 531544, 751506, 1038870, 1408048, 1875372, 2459214, 3180106, 4060860, 5126688, 6405322, 7927134, 9725256, 11835700, 14297478, 17152722, 20446804, 24228456
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

			Some solutions for n=8:
..5. .0. .5. .4. .4. .7. .7. .8. .0. .1. .1. .3. .6. .0. .2. .3
..4. .1. .0. .6. .8. .8. .6. .3. .8. .5. .5. .8. .5. .4. .0. .5
..5. .2. .7. .5. .3. .0. .0. .4. .6. .3. .6. .0. .7. .5. .4. .4
..5. .0. .7. .6. .2. .6. .4. .0. .7. .0. .8. .1. .2. .0. .2. .4
..7. .1. .4. .6. .1. .6. .5. .8. .7. .6. .1. .2. .7. .4. .3. .5
		

Crossrefs

Row 5 of A269619.

Formula

Empirical: a(n) = n^5 + 5*n^4 + 7*n^3 + 12*n^2 + 3*n.
Conjectures from Colin Barker, Jan 25 2019: (Start)
G.f.: 2*x*(14 + 27*x + 21*x^2 + x^3 - 3*x^4) / (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)

A269622 Number of length-6 0..n arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.

Original entry on oeis.org

51, 624, 3611, 14125, 43013, 110099, 248143, 507521, 961625, 1712983, 2900099, 4705013, 7361581, 11164475, 16478903, 23751049, 33519233, 46425791, 63229675, 84819773, 112228949, 146648803, 189445151, 242174225, 306599593, 384709799
Offset: 1

Views

Author

R. H. Hardin, Mar 01 2016

Keywords

Examples

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

Crossrefs

Row 6 of A269619.

Formula

Empirical: a(n) = n^6 + 6*n^5 + 9*n^4 + 22*n^3 + 9*n^2 + 9*n - 7 for n>2.
Conjectures from Colin Barker, Jan 25 2019: (Start)
G.f.: x*(51 + 267*x + 314*x^2 + 167*x^3 - 86*x^4 + 17*x^5 - 14*x^6 + 5*x^7 - x^8) / (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>9.
(End)
Showing 1-10 of 11 results. Next