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

A233320 Number A(n,k) of tilings of a k X n rectangle using trominoes of any shape; square array A(n,k), n>=0, k>=0, read by antidiagonals.

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 3, 3, 0, 1, 1, 0, 0, 10, 0, 0, 1, 1, 1, 0, 23, 23, 0, 1, 1, 1, 0, 11, 62, 0, 62, 11, 0, 1, 1, 0, 0, 170, 0, 0, 170, 0, 0, 1, 1, 1, 0, 441, 939, 0, 939, 441, 0, 1, 1, 1, 0, 41, 1173, 0, 8342, 8342, 0, 1173, 41, 0, 1
Offset: 0

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Author

Alois P. Heinz, Dec 07 2013

Keywords

Comments

Every row and column satisfies a linear recurrence. - Peter Kagey, Jul 17 2019

Examples

			Square array A(n,k) begins:
  1, 1,  1,    1,   1,    1,       1, ...
  1, 0,  0,    1,   0,    0,       1, ...
  1, 0,  0,    3,   0,    0,      11, ...
  1, 1,  3,   10,  23,   62,     170, ...
  1, 0,  0,   23,   0,    0,     939, ...
  1, 0,  0,   62,   0,    0,    8342, ...
  1, 1, 11,  170, 939, 8342,   80092, ...
  1, 0,  0,  441,   0,    0,  614581, ...
  1, 0,  0, 1173,   0,    0, 5271923, ...
		

Crossrefs

Formula

A(n,k) = 0 <=> n*k mod 3 > 0.

A270071 Number of tilings of an n X n square using monominoes and trominoes of any shape.

Original entry on oeis.org

1, 1, 5, 93, 7517, 2501946, 3473827027, 19823918037604, 466326405037190729, 45283517791861200639757, 18137923612752525595542410804, 29967243098804386765778629249653298, 204247259656641635611144023845458294818885
Offset: 0

Views

Author

Alois P. Heinz, Mar 09 2016

Keywords

Crossrefs

Main diagonal of A270061.

A270063 Number of tilings of a 3 X n rectangle using monominoes and trominoes of any shape.

Original entry on oeis.org

1, 2, 14, 93, 590, 3710, 23509, 148796, 940916, 5952243, 37655502, 238204978, 1506870209, 9532433288, 60301864000, 381467462217, 2413150656124, 15265511608858, 96569119066667, 610893045560410, 3864489168524208, 24446630393071735, 154648573589573678
Offset: 0

Views

Author

Alois P. Heinz, Mar 09 2016

Keywords

Crossrefs

Column k=3 of A270061.
Cf. A134438.

Formula

G.f.: -(x^15 +2*x^14 +5*x^13 -4*x^12 -7*x^11 -21*x^10 +12*x^9 +11*x^8 +24*x^7 -21*x^6 -13*x^5 +16*x^3 +2*x^2 +2*x -1) / (x^18 +2*x^17 +5*x^16 -9*x^15 -21*x^14 -54*x^13 +32*x^12 +46*x^11 +147*x^10 +21*x^9 -40*x^8 -110*x^7 -17*x^6 -11*x^5 -32*x^4 -37*x^3 -8*x^2 -4*x +1).

A270062 Number of tilings of a 2 X n rectangle using monominoes and trominoes of any shape.

Original entry on oeis.org

1, 1, 5, 14, 45, 140, 438, 1371, 4287, 13413, 41956, 131249, 410572, 1284352, 4017713, 12568213, 39315905, 122988066, 384731445, 1203517448, 3764844982, 11777193395, 36841433019, 115247422841, 360517151000, 1127770261265, 3527892525112, 11035958382864
Offset: 0

Views

Author

Alois P. Heinz, Mar 09 2016

Keywords

Examples

			a(3) = 14:
._____.  ._____.  ._____.  ._____.  ._____.  ._____.  ._____.
|_____|  |_|_|_|  |_____|  |_| |_|  | |_|_|  | ._|_|  |_. |_|
|_____|  |_____|  |_|_|_|  |___|_|  |___|_|  |_|_|_|  |_|_|_|
.
._____.  ._____.  ._____.  ._____.  ._____.  ._____.  ._____.
|_|_|_|  | ._| |  | |_. |  |_|_| |  |_| |_|  |_| ._|  |_|_. |
|_|_|_|  |_|___|  |___|_|  |_|___|  |_|___|  |_|_|_|  |_|_|_|  .
.
		

Crossrefs

Column k=2 of A270061.

Programs

  • Maple
    a:= n-> (Matrix(6, (i, j)-> `if`(i+1=j, 1, `if`(i=6, [-1$2, 1,
             5$2, 1][j], 0)))^n. <<1, 1, 5, 14, 45, 140>>)[1, 1]:
    seq(a(n), n=0..30);

Formula

G.f.: -(x^3+x^2-1)/(x^6+x^5-x^4-5*x^3-5*x^2-x+1).
a(n) = a(n-1) +5*(a(n-2)+a(n-3)) +a(n-4) -a(n-5) -a(n-6).

A270064 Number of tilings of a 4 X n rectangle using monominoes and trominoes of any shape.

Original entry on oeis.org

1, 3, 45, 590, 7517, 96176, 1238818, 15913695, 204383373, 2626057921, 33738191906, 433438712623, 5568545948434, 71541033899738, 919110571684493, 11808116466700575, 151702772808195855, 1948975423808006804, 25039128916718657873, 321685935180001027054
Offset: 0

Views

Author

Alois P. Heinz, Mar 09 2016

Keywords

Crossrefs

Column k=4 of A270061.

Formula

G.f.: -(x^42 -2*x^41 +3*x^40 -45*x^39 +75*x^38 -104*x^37 +788*x^36 -1328*x^35 +1326*x^34 -8174*x^33 +13318*x^32 -9055*x^31 +51980*x^30 -68274*x^29 +18138*x^28 -163965*x^27 +144209*x^26 +50099*x^25 +307359*x^24 -237066*x^23 -88998*x^22 -420220*x^21 +288839*x^20
+56875*x^19 +263379*x^18 -179966*x^17 +19258*x^16 -47380*x^15 +99349*x^14 -28851*x^13 -16616*x^12 -21781*x^11 +15041*x^10 -705*x^9 -2136*x^8 -1268*x^7 +2193*x^6 +558*x^5 -149*x^4 -187*x^3 -25*x^2 -4*x +1)
/ (x^45 -2*x^44 +4*x^43 -58*x^42 +90*x^41 -162*x^40 +1072*x^39 -1745*x^38 +1906*x^37 -10656*x^36 +21746*x^35 -17639*x^34 +90014*x^33 -190035*x^32 +136443*x^31 -516421*x^30 +828239*x^29 -326624*x^28 +1290743*x^27 -1284720*x^26 -519116*x^25 -1599589*x^24 +1444541*x^23 +956723*x^22
+2264534*x^21 -1759452*x^20 -691070*x^19 -1308065*x^18 +953491*x^17 +192415*x^16 +204107*x^15 -475505*x^14 +77942*x^13 +133756*x^12 +68320*x^11 -73312*x^10 -9470*x^9 +10934*x^8 +4282*x^7 -4428*x^6 -1244*x^5 +386*x^4 +315*x^3 +49*x^2 +7*x -1).

A270065 Number of tilings of a 5 X n rectangle using monominoes and trominoes of any shape.

Original entry on oeis.org

1, 4, 140, 3710, 96176, 2501946, 65410388, 1707101599, 44538604036, 1162378878394, 30334909910156, 791636651386694, 20659194865202206, 539139829390310029, 14069828639020139191, 367177676400256677129, 9582168262012437486944, 250064069442551102774366
Offset: 0

Views

Author

Alois P. Heinz, Mar 09 2016

Keywords

Crossrefs

Column k=5 of A270061.

A270066 Number of tilings of a 6 X n rectangle using monominoes and trominoes of any shape.

Original entry on oeis.org

1, 6, 438, 23509, 1238818, 65410388, 3473827027, 184140417890, 9756894398324, 517174361985073, 27412100990502042, 1452889626133073024, 77006768282516987969, 4081555197498259422846, 216332403430110823588762, 11466150014825389043509015
Offset: 0

Views

Author

Alois P. Heinz, Mar 09 2016

Keywords

Crossrefs

Column k=6 of A270061.

A270067 Number of tilings of a 7 X n rectangle using monominoes and trominoes of any shape.

Original entry on oeis.org

1, 9, 1371, 148796, 15913695, 1707101599, 184140417890, 19823918037604, 2133436326533143, 229681994753502100, 24725866354382952217, 2661724100255128134369, 286536699674194768262220, 30845921492404301091244774, 3320584102598070051873302366
Offset: 0

Views

Author

Alois P. Heinz, Mar 09 2016

Keywords

Crossrefs

Column k=7 of A270061.

A270068 Number of tilings of an 8 X n rectangle using monominoes and trominoes of any shape.

Original entry on oeis.org

1, 13, 4287, 940916, 204383373, 44538604036, 9756894398324, 2133436326533143, 466326405037190729, 101965922336345576219, 22294594753523459270694, 4874505512330163994345181, 1065778806957316983452583926, 233025803338941141247495062594
Offset: 0

Views

Author

Alois P. Heinz, Mar 09 2016

Keywords

Crossrefs

Column k=8 of A270061.

A270069 Number of tilings of a 9 X n rectangle using monominoes and trominoes of any shape.

Original entry on oeis.org

1, 19, 13413, 5952243, 2626057921, 1162378878394, 517174361985073, 229681994753502100, 101965922336345576219, 45283517791861200639757, 20109634299824273864511862, 8930062817269356408791188106, 3965614916098256915340694883017, 1761030770921730133912679646624228
Offset: 0

Views

Author

Alois P. Heinz, Mar 09 2016

Keywords

Crossrefs

Column k=9 of A270061.
Showing 1-10 of 11 results. Next