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

A269461 Number of length-n 0..2 arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

3, 9, 24, 66, 174, 462, 1206, 3150, 8166, 21150, 54582, 140718, 362118, 931134, 2391894, 6141006, 15757734, 40420062, 103647606, 265721070, 681097926, 1745555070, 4473092502, 11461604238, 29366557158, 75238139934, 192754700214
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Comments

Column 2 of A269467.

Examples

			Some solutions for n=9:
..1. .1. .0. .2. .1. .0. .1. .2. .2. .1. .1. .0. .2. .2. .0. .2
..1. .2. .1. .2. .2. .1. .0. .1. .1. .0. .1. .2. .0. .1. .1. .1
..0. .2. .2. .1. .1. .2. .1. .1. .0. .0. .0. .1. .1. .1. .0. .1
..2. .0. .2. .2. .2. .2. .2. .0. .0. .1. .2. .2. .1. .0. .1. .2
..2. .1. .0. .0. .0. .1. .2. .2. .2. .2. .0. .0. .2. .0. .0. .0
..1. .0. .2. .1. .1. .0. .0. .2. .1. .2. .0. .1. .1. .2. .2. .0
..2. .1. .1. .1. .0. .2. .2. .1. .1. .0. .1. .0. .0. .2. .1. .2
..0. .1. .2. .0. .0. .1. .1. .0. .0. .2. .2. .1. .2. .1. .1. .2
..1. .0. .1. .0. .1. .0. .0. .1. .1. .1. .2. .0. .0. .1. .2. .0
		

Crossrefs

Cf. A269467.

Formula

Empirical: a(n) = 3*a(n-1) + 2*a(n-2) - 8*a(n-3).
Conjectures from Colin Barker, Mar 21 2018: (Start)
G.f.: 3*x*(1 - 3*x^2) / ((1 - 2*x)*(1 - x - 4*x^2)).
a(n) = 2^(-4-n)*(-51*4^(1+n) + (255-57*sqrt(17))*(1-sqrt(17))^n + 3*(1+sqrt(17))^n*(85+19*sqrt(17))) / 17.
(End)

A269460 Number of length-n 0..n arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

2, 9, 60, 580, 7170, 108402, 1934856, 39808584, 927352710, 24123618310, 693066874236, 21793557008028, 744461976979994, 27451268150267850, 1086741065393740560, 45971289976043485456, 2069440771476789080334
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Comments

Diagonal of A269467.

Examples

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

Crossrefs

Cf. A269467.

A269462 Number of length-n 0..3 arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

4, 16, 60, 228, 852, 3180, 11796, 43644, 160980, 592572, 2177268, 7988700, 29277204, 107195196, 392179380, 1433907228, 5240022612, 19140884220, 69894090996, 255150047964, 931214323860, 3397977981372, 12397189043508, 45224087388060
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Examples

			Some solutions for n=9:
..1. .1. .2. .2. .0. .0. .1. .2. .1. .2. .0. .2. .1. .1. .1. .0
..0. .1. .1. .1. .3. .2. .3. .0. .2. .1. .1. .1. .3. .2. .2. .1
..1. .2. .2. .3. .1. .0. .2. .0. .1. .0. .3. .2. .3. .0. .2. .0
..0. .1. .3. .0. .3. .0. .1. .2. .0. .0. .0. .1. .0. .3. .1. .1
..1. .2. .0. .1. .1. .1. .0. .2. .3. .1. .2. .1. .3. .3. .1. .0
..2. .3. .3. .2. .3. .2. .1. .0. .1. .3. .1. .3. .2. .1. .0. .0
..0. .0. .0. .2. .1. .3. .2. .0. .3. .2. .1. .1. .3. .3. .3. .1
..2. .0. .1. .0. .3. .0. .0. .2. .3. .0. .2. .0. .1. .2. .0. .1
..2. .3. .0. .0. .2. .2. .3. .2. .2. .2. .2. .0. .0. .2. .0. .0
		

Crossrefs

Column 3 of A269467.

Formula

Empirical: a(n) = 5*a(n-1) - 18*a(n-3).
Conjectures from Colin Barker, Jan 22 2019: (Start)
G.f.: 4*x*(1 - x - 5*x^2) / ((1 - 3*x)*(1 - 2*x - 6*x^2)).
a(n) = (-28*3^n + (49-17*sqrt(7))*(1-sqrt(7))^n + (1+sqrt(7))^n*(49+17*sqrt(7))) / 63.
(End)

A269463 Number of length-n 0..4 arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

5, 25, 120, 580, 2780, 13300, 63420, 301780, 1433180, 6795700, 32180220, 152216980, 719335580, 3396714100, 16028713020, 75595396180, 356358069980, 1679206088500, 7909957661820, 37249421039380, 175371521796380, 825484323238900
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Examples

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

Crossrefs

Column 4 of A269467.

Formula

Empirical: a(n) = 7*a(n-1) - 4*a(n-2) - 32*a(n-3).
Empirical g.f.: 5*x*(1 - 2*x - 7*x^2) / ((1 - 4*x)*(1 - 3*x - 8*x^2)). - Colin Barker, Jan 22 2019

A269464 Number of length-n 0..5 arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

6, 36, 210, 1230, 7170, 41730, 242370, 1405530, 8139570, 47082330, 272068770, 1570817130, 9062549970, 52251339930, 301095703170, 1734220430730, 9984459848370, 57463149169530, 330612722505570, 1901660018436330
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Examples

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

Crossrefs

Column 5 of A269467.

Formula

Empirical: a(n) = 9*a(n-1) - 10*a(n-2) - 50*a(n-3).
Conjectures from Colin Barker, Jan 22 2019: (Start)
G.f.: 6*x*(1 - 3*x - 9*x^2) / ((1 - 5*x)*(1 - 4*x - 10*x^2)).
a(n) = (-84*5^n + (231-57*sqrt(14))*(2-sqrt(14))^n + 3*(2+sqrt(14))^n*(77+19*sqrt(14))) / 350.
(End)

A269465 Number of length-n 0..6 arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

7, 49, 336, 2310, 15834, 108402, 741090, 5060706, 34523202, 235304034, 1602555906, 10906971810, 74188793154, 504367206882, 3427339028610, 23280526483746, 158079249910722, 1073053862250594, 7281968079533826, 49404973360789410
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Examples

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

Crossrefs

Column 6 of A269467.

Formula

Empirical: a(n) = 11*a(n-1) -18*a(n-2) -72*a(n-3).
Conjectures from Colin Barker, Jan 22 2019: (Start)
G.f.: 7*x*(1 - 4*x - 11*x^2) / ((1 - 6*x)*(1 - 5*x - 12*x^2)).
a(n) = (7/657)*2^(-4-n) * (-73*3^n*4^(1+n) + (949-103*sqrt(73))*(5-sqrt(73))^n + (5+sqrt(73))^n*(949+103*sqrt(73))).
(End)

A269466 Number of length-n 0..7 arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

8, 64, 504, 3976, 31304, 246232, 1934856, 15190840, 119174216, 934305400, 7320389832, 57325443448, 448697920328, 3510562344184, 27455875247304, 214658236385656, 1677757456358984, 13109740539632632, 102412911071378376
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Examples

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

Crossrefs

Column 7 of A269467.

Formula

Empirical: a(n) = 13*a(n-1) -28*a(n-2) -98*a(n-3).
Conjectures from Colin Barker, Jan 22 2019: (Start)
G.f.: 8*x*(1 - 5*x - 13*x^2) / ((1 - 7*x)*(1 - 6*x - 14*x^2)).
a(n) = 2*(-92*7^n + (345-67*sqrt(23))*(3-sqrt(23))^n + (3+sqrt(23))^n*(345+67*sqrt(23))) / 1127.
(End)

A269468 Number of length-4 0..n arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

10, 66, 228, 580, 1230, 2310, 3976, 6408, 9810, 14410, 20460, 28236, 38038, 50190, 65040, 82960, 104346, 129618, 159220, 193620, 233310, 278806, 330648, 389400, 455650, 530010, 613116, 705628, 808230, 921630, 1046560, 1183776, 1334058
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Examples

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

Crossrefs

Row 4 of A269467.

Formula

Empirical: a(n) = n^4 + 4*n^3 + 4*n^2 + n.
Conjectures from Colin Barker, Jan 23 2019: (Start)
G.f.: 2*x*(5 + 8*x - x^2) / (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)

A269469 Number of length-5 0..n arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

14, 174, 852, 2780, 7170, 15834, 31304, 56952, 97110, 157190, 243804, 364884, 529802, 749490, 1036560, 1405424, 1872414, 2455902, 3176420, 4056780, 5122194, 6400394, 7921752, 9719400, 11829350, 14290614, 17145324, 20438852, 24219930
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Examples

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

Crossrefs

Row 5 of A269467.

Formula

Empirical: a(n) = n^5 + 5*n^4 + 7*n^3 + 2*n^2 - n.
Conjectures from Colin Barker, Jan 23 2019: (Start)
G.f.: 2*x*(7 + 45*x + 9*x^2 - x^3) / (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)

A269470 Number of length-6 0..n arrays with no repeated value equal to the previous repeated value.

Original entry on oeis.org

22, 462, 3180, 13300, 41730, 108402, 246232, 505800, 960750, 1713910, 2904132, 4713852, 7377370, 11189850, 16517040, 23805712, 33594822, 46527390, 63363100, 84991620, 112446642, 146920642, 189780360, 242583000, 307093150, 385300422
Offset: 1

Views

Author

R. H. Hardin, Feb 27 2016

Keywords

Examples

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

Crossrefs

Row 6 of A269467.

Formula

Empirical: a(n) = n^6 + 6*n^5 + 11*n^4 + 4*n^3 - n^2 + n.
Conjectures from Colin Barker, Jan 23 2019: (Start)
G.f.: 2*x*(11 + 154*x + 204*x^2 - 14*x^3 + 5*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)
Showing 1-10 of 11 results. Next