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 1-7 of 7 results.

A269103 Number of n X 2 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

Original entry on oeis.org

16, 180, 1740, 15540, 132300, 1090740, 8787660, 69580980, 543538380, 4200069300, 32167589580, 244542858420, 1847388128460, 13880833735860, 103809654007500, 773174303047860, 5737767196302540, 42443199898890420, 313054205965641420
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Column 2 of A269109.

Examples

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

Crossrefs

Cf. A269109.

Formula

Empirical: a(n) = 14*a(n-1) - 49*a(n-2) for n>3.
Conjectures from Colin Barker, Mar 21 2018: (Start)
G.f.: 4*x*(4 - 11*x + x^2) / (1 - 7*x)^2.
a(n) = 60*7^(n-3)*(8*n+5) for n>1.
(End)

A269102 Number of n X n 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

Original entry on oeis.org

4, 180, 40908, 43964700, 232068730044, 6206909793496236, 858502190008810133292, 622342168717398556687064028, 2386083493285894017930101786679468
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Diagonal of A269109.

Examples

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

Crossrefs

Cf. A269109.

A269104 Number of n X 3 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

Original entry on oeis.org

60, 1740, 40908, 872460, 17593092, 342055548, 6482020140, 120520189980, 2208175854948, 39988864047276, 717328864510092, 12766536225007020, 225704408971133124, 3967699804321484124, 69407066832964073964
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Examples

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

Crossrefs

Column 3 of A269109.

Formula

Empirical: a(n) = 36*a(n-1) - 378*a(n-2) + 972*a(n-3) - 729*a(n-4) for n>5.
Empirical g.f.: 12*x*(5 - 35*x + 79*x^2 - 69*x^3 + 18*x^4) / (1 - 18*x + 27*x^2)^2. - Colin Barker, Jan 19 2019

A269105 Number of nX4 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

Original entry on oeis.org

216, 15540, 872460, 43964700, 2085484068, 95166487524, 4227147007836, 184069947098892, 7894012975085748, 334480929126425748, 14034341507370527532, 584107408947764887164, 24145251769444080595908
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Column 4 of A269109.

Examples

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

Crossrefs

Cf. A269109.

Formula

Empirical: a(n) = 90*a(n-1) -2559*a(n-2) +24556*a(n-3) -94959*a(n-4) +140442*a(n-5) -69169*a(n-6) for n>7

A269106 Number of n X 5 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

Original entry on oeis.org

756, 132300, 17593092, 2085484068, 232068730044, 24808345933548, 2579398703502996, 262780733311913580, 26357371124964908460, 2611360040338484328156, 256155579492309832819860
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Column 5 of A269109.

Examples

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

Crossrefs

Cf. A269109.

Formula

Empirical: a(n) = 236*a(n-1) -19546*a(n-2) +707906*a(n-3) -13261621*a(n-4) +137719076*a(n-5) -784626841*a(n-6) +2025590366*a(n-7) +1091882414*a(n-8) -18874661724*a(n-9) +33829878231*a(n-10) +10605114324*a(n-11) -91783964484*a(n-12) +94503314304*a(n-13) -30762353664*a(n-14) for n>15.

A269107 Number of nX6 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

Original entry on oeis.org

2592, 1090740, 342055548, 95166487524, 24808345933548, 6206909793496236, 1509593256271433868, 359627971978314972756, 84330282164848323860700, 19529981463869576058830652, 4477577440675705031339912748
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Column 6 of A269109.

Examples

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

Crossrefs

Cf. A269109.

Formula

Empirical: a(n) = 624*a(n-1) -148392*a(n-2) +17707654*a(n-3) -1237692774*a(n-4) +55270649556*a(n-5) -1656470723141*a(n-6) +34132157660412*a(n-7) -484096890617541*a(n-8) +4569992373952272*a(n-9) -25146261177957786*a(n-10) +25694778316842858*a(n-11) +756190434082200840*a(n-12) -6052462771631752224*a(n-13) +18126128855859433455*a(n-14) +18664609483184919500*a(n-15) -342070453287924453888*a(n-16) +1141375792492508055684*a(n-17) -1231488788816842507708*a(n-18) -2418565901590843869576*a(n-19) +9095171580512370570684*a(n-20) -8677540039273932904920*a(n-21) -4965678440542161492372*a(n-22) +17155105764294227912496*a(n-23) -13588702943203699236720*a(n-24) +4184136771765648014016*a(n-25) -441364595341874186304*a(n-26) for n>27

A269108 Number of n X 7 0..3 arrays with some element plus some horizontally or vertically adjacent neighbor totalling three no more than once.

Original entry on oeis.org

8748, 8787660, 6482020140, 4227147007836, 2579398703502996, 1509593256271433868, 858502190008810133292, 478110059855042497842996, 262048541877700400412558012, 141832398849461215193264315676
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2016

Keywords

Comments

Column 7 of A269109.

Examples

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

Crossrefs

Cf. A269109.

Formula

Empirical recurrence of order 64 (see link above).
Showing 1-7 of 7 results.