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.

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A233428 Number of tilings of a 3 X 5n rectangle with 3n pentominoes of any shape.

Original entry on oeis.org

1, 56, 7670, 1082911, 153054306, 21632866165, 3057616805283, 432167457281031, 61083099363540480, 8633563135788393662, 1220278820098831948033, 172475764103555415010594, 24377944378888377125376221, 3445609736701113995818305965, 487006872816193035818432289071
Offset: 0

Views

Author

Alois P. Heinz, Dec 09 2013

Keywords

Crossrefs

Quintisection of column k=3 of A233427.

Formula

From Vaclav Kotesovec, Mar 05 2016: (Start)
a(n) ~ c * d^n, where d = 141.34127484863151940788399760068559708960763498273966116022774034..., c = 0.3835032349236650628846889495224683008372791393401511291113817887...
a(n) = 172*a(n-1) - 4716*a(n-2) + 56595*a(n-3) - 364164*a(n-4) + 1353076*a(n-5) - 3014276*a(n-6) + 4180766*a(n-7) - 3711813*a(n-8) + 2129818*a(n-9) - 781787*a(n-10) + 178168*a(n-11) - 24000*a(n-12) + 1780*a(n-13) - 67*a(n-14) + a(n-15).
G.f.: (-1 + 116*x - 2754*x^2 + 28828*x^3 - 160178*x^4 + 509733*x^5 - 963854*x^6 + 1114401*x^7 - 801386*x^8 + 358357*x^9 - 97595*x^10 + 15483*x^11 - 1335*x^12 + 58*x^13 - x^14)/( - 1 + 172*x - 4716*x^2 + 56595*x^3 - 364164*x^4 + 1353076*x^5 - 3014276*x^6 + 4180766*x^7 - 3711813*x^8 + 2129818*x^9 - 781787*x^10 + 178168*x^11 - 24000*x^12 + 1780*x^13 - 67*x^14 + x^15).
(End)

A233429 Number of tilings of a 4 X 5n rectangle with 4n pentominoes of any shape.

Original entry on oeis.org

1, 501, 890989, 1666772813, 3125064284901, 5859766228545967, 10987595369808657169, 20602741350971679371521, 38632014757792375332001835, 72438542874037975287077565935, 135828859204452470219311220073385, 254691470323770059993623356733063003
Offset: 0

Views

Author

Alois P. Heinz, Dec 09 2013

Keywords

Crossrefs

Quintisection of column k=4 of A233427.

Formula

a(n) ~ c * d^n, where d = 1875.09099182186211660253860201132854810972459605757360689785461004..., c = 0.25279505771792803447854701369537504374767224177480509542292622525... . - Vaclav Kotesovec, Mar 05 2016

A246764 Number of tilings of a 5 X n rectangle using n pentominoes of shapes P, I, N, T.

Original entry on oeis.org

1, 1, 3, 7, 17, 78, 247, 916, 3301, 11272, 41854, 150485, 538585, 1954912, 6978464, 25170446, 90851829, 326048198, 1176355862, 4230352602, 15222263126, 54855015353, 197302183497, 710556528403, 2557837610375, 9205575728179, 33148388282116, 119307072980025
Offset: 0

Views

Author

Alois P. Heinz, Nov 28 2014

Keywords

Crossrefs

A246902 Number of tilings of a 5 X n rectangle using n pentominoes of distinct shapes.

Original entry on oeis.org

1, 1, 0, 28, 200, 856, 2164, 5584, 13632, 23608, 27804, 16412, 4040
Offset: 0

Views

Author

Alois P. Heinz, Nov 16 2014

Keywords

Examples

			a(3) = 28: 4 orientations of each of the following 7 patterns:
  ._____. ._____. ._____. ._____. ._____. ._____. ._____.
  |___. | | |   | |_. ._| | .___| |   | | |_.   | | ._| |
  | | | | | | ._| | | | | | |   | | ._| | | |___| | |_. |
  | | |_| | |_| | | |_| | |_| ._| |_| ._| |_. ._| |___| |
  | |_. | |___| | | |_. | | |_| | | |_| | | |_| | |   |_|
  |___|_| |_____| |___|_| |_____| |_____| |_____| |_____| .
		

Crossrefs

A247121 Number of tilings of a 5 X 2n rectangle using 2n pentominoes of shapes P, U.

Original entry on oeis.org

1, 2, 12, 56, 248, 1184, 5472, 25376, 118208, 548864, 2550912, 11856896, 55098368, 256070144, 1190065152, 5530658816, 25703241728, 119453057024, 555145224192, 2579979739136, 11990182412288, 55723107221504, 258967268524032, 1203523043065856, 5593246378754048
Offset: 0

Views

Author

Alois P. Heinz, Nov 19 2014

Keywords

Examples

			a(2) = 12:
._______.      ._______.      ._______.      ._______.
|   |   |      |   ._| |      | ._|   |      | ._|   |
| ._| ._|      |___|   |      | |_____|      | |_____|
|_| |_| |      |   |___|      |___|   |      |___|_. |
|   |   |      | ._|   |      |   |_. |      |   ._| |
|___|___| (*4) |_|_____| (*2) |_____|_| (*4) |___|___| (*2) .
		

Crossrefs

Programs

  • Maple
    a:= n-> ceil((<<0|1|0>, <0|0|1>, <20|8|2>>^(n-1). <<2, 12, 56>>)[1, 1]):
    seq(a(n), n=0..30);

Formula

G.f.: (4*x^3-1)/(20*x^3+8*x^2+2*x-1).

A247127 Number of tilings of a 5 X n rectangle using n pentominoes of shapes V, U, X, N.

Original entry on oeis.org

1, 0, 0, 1, 4, 0, 9, 8, 24, 17, 78, 64, 227, 212, 664, 699, 2004, 2220, 6033, 7196, 18112, 22859, 54882, 72560, 166251, 229284, 505632, 721421, 1540532, 2264668, 4702135, 7092742, 14376450, 22165709, 44024116, 69154334, 134973515, 215459398, 414268932
Offset: 0

Views

Author

Alois P. Heinz, Nov 19 2014

Keywords

Crossrefs

Programs

  • Maple
    gf:= -(4*x^18 +4*x^17 -8*x^16 -3*x^15 -9*x^14 +2*x^13 -3*x^12 +5*x^11 -7*x^10 +x^9 -7*x^8 -x^6 -2*x^5 -x^3+1) / (32*x^26 +32*x^25 -32*x^24 +8*x^23 -120*x^22 +12*x^21 -124*x^20 +36*x^19 -123*x^18 +35*x^17 -106*x^16 +20*x^15 -62*x^14 -23*x^13 -22*x^12 -36*x^11 +5*x^10 -18*x^9 +13*x^8 -4*x^7 +8*x^6 +2*x^5 +4*x^4 +2*x^3-1):
    a:= n-> coeff(series(gf, x, n+1), x, n):
    seq(a(n), n=0..50);

Formula

G.f.: see Maple program.

A247735 Total number of F shapes in all tilings of a 5 X n rectangle with pentominoes of any shape.

Original entry on oeis.org

0, 0, 0, 4, 68, 744, 7088, 69176, 658776, 5995348, 52831448, 458439732, 3944077760, 33606901296, 283630894720, 2375471834288, 19779055344468, 163866917256420, 1351464466008112, 11100931884955344, 90860898121739864, 741378713523090200, 6032337718479599100
Offset: 0

Views

Author

Alois P. Heinz, Sep 23 2014

Keywords

Crossrefs

Formula

a(n) = Sum_{k>0} k * A247702(n,k).

A247736 Total number of I shapes in all tilings of a 5 X n rectangle with pentominoes of any shape.

Original entry on oeis.org

0, 1, 2, 11, 122, 2278, 17502, 140037, 1250890, 11184764, 96901618, 810143038, 6787465080, 56871594099, 473417649550, 3913478050583, 32192184170708, 264014564271675, 2158561440821352, 17592866753339355, 142983916007396542, 1159269824603687631, 9378694043134778568
Offset: 0

Views

Author

Alois P. Heinz, Sep 23 2014

Keywords

Crossrefs

Formula

a(n) = Sum_{k>0} k * A247703(n,k).

A247737 Total number of L shapes in all tilings of a 5 X n rectangle with pentominoes of any shape.

Original entry on oeis.org

0, 0, 4, 24, 436, 3888, 29880, 264460, 2353136, 20400352, 171215320, 1430108512, 11962161392, 99523393628, 822501750184, 6763177931936, 55433124540308, 453013557727460, 3690931980743340, 29988435689294280, 243064471330287696, 1965884816120576180
Offset: 0

Views

Author

Alois P. Heinz, Sep 23 2014

Keywords

Crossrefs

Formula

a(n) = Sum_{k>0} k * A247704(n,k).

A247738 Total number of N shapes in all tilings of a 5 X n rectangle with pentominoes of any shape.

Original entry on oeis.org

0, 0, 0, 8, 88, 1024, 10388, 99840, 935900, 8415368, 74295280, 645535244, 5545784444, 47152918764, 397457338488, 3327197881716, 27688757985292, 229256300558340, 1889667799688076, 15514699106805468, 126939424800685264, 1035396864840877088, 8421920979218715332
Offset: 0

Views

Author

Alois P. Heinz, Sep 23 2014

Keywords

Crossrefs

Formula

a(n) = Sum_{k>0} k * A247705(n,k).
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