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.

Previous Showing 11-14 of 14 results.

A359026 Number of inequivalent tilings of a 10 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

1, 1, 51, 347, 7048, 130125, 2551794, 49828415
Offset: 0

Views

Author

John Mason, Dec 12 2022

Keywords

Crossrefs

Column k = 10 of A227690.
Sequences for fixed and free (inequivalent) tilings of m X n rectangles, for 2 <= m <= 10:

A226548 Number of squares in all tilings of a 5 X n rectangle using integer-sided square tiles.

Original entry on oeis.org

0, 5, 50, 256, 1402, 6940, 33502, 157279, 725080, 3293575, 14789640, 65785991, 290341336, 1272947979, 5549535668, 24075671345, 104002776564, 447586575256, 1919810662952, 8210002538205, 35015688030978, 148980204943747, 632466650426456, 2679623444793841
Offset: 0

Views

Author

Alois P. Heinz, Jun 10 2013

Keywords

Crossrefs

Column k=5 of A226545.
Cf. A054857.

Formula

G.f.: (x^10 +12*x^9 +28*x^8 +54*x^7 +33*x^6 +18*x^5 -53*x^4 -42*x^3 +6*x^2 +30*x+5)*x / (x^8 +3*x^7 +2*x^6 +5*x^5 +x^4 -6*x^3 -7*x^2 -2*x+1)^2.

A362146 Maximum number of ways in which a set of integer-sided squares can tile an n X 5 rectangle.

Original entry on oeis.org

1, 1, 4, 12, 37, 140, 454, 1566, 5670, 18738, 70800, 263002, 1065240, 4146500, 15269976, 61593260, 233206636, 879932068, 3442083056, 12794936028, 49150133908, 188187379818, 690417160564, 2688772826468, 10355819787218, 42350139855568, 167122149149460
Offset: 0

Views

Author

Pontus von Brömssen, Apr 10 2023

Keywords

Crossrefs

Fifth column of A362142.

A054858 Number of basic blocks of size 5xn for tilings with square tiles of size up to 5 X 5.

Original entry on oeis.org

1, 7, 13, 20, 35, 66, 118, 218, 402, 738, 1358, 2498, 4594, 8450, 15542, 28586, 52578, 96706, 177870, 327154, 601730, 1106754, 2035638, 3744122, 6886514, 12666274, 23296910, 42849698, 78812882, 144959490, 266622070
Offset: 1

Views

Author

Silvia Heubach (silvi(AT)cine.net), Apr 21 2000

Keywords

Comments

Basic blocks of size 5xn are tilings of a 5xn area that cannot be vertically split into two smaller tilings of size 5xk and 5x(n-k).

Examples

			a(3)=7 as the nature of basic blocks requires that the tiling cannot be split vertically into smaller tilings. Thus there needs to be one 2 X 2 tile whose lower left corner is in column 1 and one whose llc is in column 2. There are 7 ways to place these two 2 X 2 tiles.
		

Crossrefs

Cf. A054857.

Programs

  • Mathematica
    f[ {A_, B_} ] := Module[ {til = A, basic = B}, {Flatten[ Append[ til, ListConvolve[ A, B ] ]], AppendTo[ basic, B[[ -1 ]] + B[[ -2 ]] + B[[ -3 ] ]]} ]; NumOfBasicBlocks[ n_ ] := Nest[ f, {{1, 1, 8, 28, 117, 472, 1916, 7765}, {1, 7, 13, 20, 35, 66, 118, 218}}, n-2 ][[ 2 ]] NumOfBasicBlocks[ 30 ]
    LinearRecurrence[{1,1,1},{1,7,13,20,35,66,118,218},40] (* Harvey P. Dale, Dec 06 2018 *)

Formula

a(n) = a(n-1)+a(n-2)+a(n-3) for n>8, a(1)=1, a(2)=7, a(3)=13, a(4)=20, a(5)=35, a(6)=66, a(7)=218
G.f.: x^5+2*x^4-x^3+5*x^2-x-10+2*(-4*x+5-5*x^2)/(1-x-x^2-x^3). a(n) = 10*A000213(n)-8*A000073(n+1), n>5. [R. J. Mathar, Nov 02 2008]
Previous Showing 11-14 of 14 results.