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 1-2 of 2 results.

A233289 Number of tilings of a 3 X 3 X n box using 3n bricks of shape 3 X 1 X 1.

Original entry on oeis.org

1, 2, 4, 21, 92, 320, 1213, 4822, 18556, 70929, 273808, 1057020, 4069737, 15676666, 60424640, 232846801, 897164316, 3457096532, 13321674833, 51332757274, 197801848744, 762200458321, 2937024077340, 11317358546188, 43609682555721, 168043191679374
Offset: 0

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Author

Alois P. Heinz, Dec 06 2013

Keywords

Comments

This is a variant of the Jenga game (see link).

Crossrefs

Column k=3 of A233308.

Programs

  • Maple
    gf:= (x^7-x^6+x^5-x^4+4*x^3+2*x^2+x-1)/(-x^10+x^9
         -3*x^8+4*x^7-7*x^6-11*x^5+2*x^4+13*x^3+3*x-1):
    a:= n-> coeff(series(gf, x, n+1), x, n):
    seq(a(n), n=0..30);

Formula

G.f.: (x^7 -x^6 +x^5 -x^4 +4*x^3 +2*x^2 +x -1) / (-x^10 +x^9 -3*x^8 +4*x^7 -7*x^6 -11*x^5 +2*x^4 +13*x^3 +3*x -1).

A237355 The number of tilings of the 3 X 4 X n room by 1 X 1 X 3 boxes.

Original entry on oeis.org

1, 3, 9, 92, 749, 4430, 30076, 217579, 1479055, 10046609, 69575902, 479035195, 3284657308, 22593041544, 155444686265, 1068352050847, 7344626541715, 50504764148658, 347234420131143, 2387280989007848, 16413850076764282, 112852648679477233, 775901649656851817
Offset: 0

Views

Author

R. J. Mathar, Feb 07 2014

Keywords

Comments

The count compiles all arrangements without respect to symmetry: Stacks that are equivalent after rotations or flips through any of the 3 axes or 3 planes are counted with multiplicity.
The rational generating function p(x)/q(x) is qualified in the Maple section for argument x=z^4.

Crossrefs

Cf. A233247 (2 X 3 X n rooms), A233289 (3 X 3 X n rooms), A273474.

Programs

  • Maple
    A237355 := proc(n)
    p :=
    -(-1 +3396185*z^268 +126*z^12 -1276*z^28 +5*z^8 +
    5283231061*z^124-1577588*z^52 -13645425693*z^152 +
    144704015*z^244 -455*z^20 +13238456*z^260 +31819046103*z
    ^156 -z^320 +25108196325*z^148 -93044*z^44 -2901338989*z
    ^128 -10*z^336 -2163597596*z^216 +10067*z^32 -29481842170
    *z^168 -27774785437*z^144 +2*z^4 -4*z^340 -18745905736
    *z^176 +7299716699*z^140 +21*z^332 -501*z^312 +
    32101048863*z^172 -71881307*z^76 +153863*z^36 +13993826*z
    ^64 +35536*z^292 +10372*z^300 -21028*z^296 -28*z^324
    +21886734767*z^180 +2407716*z^68 +91622*z^40 -23376175*z
    ^80 -24005339291*z^184 +100677112*z^92 -7169*z^304 +1184*
    z^316 +222741*z^56 -192795426*z^100 +5270172488*z^108 -
    57*z^328 +25361870*z^252 -4094967*z^264 +943065389*z^
    116 +19724145370*z^132 -32733186254*z^160 +18663190295*z^
    164 +561417344*z^84 -1224595901*z^224 +14015301065*z^188 -
    2024669*z^272 -11369197887*z^120 +337006779*z^236 -
    990719131*z^112 -25766687*z^256 -6333*z^24 +207060338*z^
    88 +19722918*z^60 -123289650*z^72 -73800398*z^248 +651316
    *z^276 -309189319*z^104 -93*z^16 -14025522915*z^136 -
    2171925*z^48 +13808940292*z^196 +671*z^308 +2217864262*z
    ^220 -634809849*z^232 +617029016*z^228 +259296*z^284 -
    7967920024*z^200 -6205639852*z^208 +3519281640*z^212 +
    5961180966*z^204 +z^348 -12884456696*z^192 -1943914891*z^
    96 -105001*z^288 -138606683*z^240 -319172*z^280) ;
    p := algsubs(z^4=x,p) ;
    q :=
    1-
    60815785*z^268 -176*z^12 -1074*z^28 +z^8 -2139678101*z
    ^124 +4517295*z^52 +32366552001*z^152 -1795023861*z^244 +
    293*z^20 -196601781*z^260 -132185701967*z^156 +1278*z^
    320 -71881449601*z^148 +59839*z^44 -2160878871*z^128 -65*
    z^336 +22568613842*z^216 -7860*z^32 +142211822794*z^168 +
    104511366128*z^144 -5*z^4 -65*z^340 +91273082294*z^176
    -6729477185*z^140 +85*z^332 +12778*z^312 -144862794083*z
    ^172 +339177827*z^76 -272389*z^36 -50928278*z^64 -559851*
    z^292 -211745*z^300 +506788*z^296 -130*z^324 -
    126560496081*z^180 -5385773*z^68 -183389*z^40 +33326860*z
    ^80 +132197432121*z^184 -41410295*z^92 +55563*z^304 -
    12700*z^316 +105217*z^56 +3679914785*z^100 -17881094620*z
    ^108 +1761*z^328 -436930703*z^252 +z^360 +73736037*z^
    264 +1839198593*z^116 -70543105470*z^132 +119917584642*z^
    160 -67890453774*z^164 -1656296393*z^84 +12491943945*z^224
    -86012823396*z^188 +31180618*z^272 -7*z^352 +39629953212*
    z^120 -3979624295*z^236 -4934247701*z^112 +375021274*z^
    256 +10064*z^24 -1420714989*z^88 -44954256*z^60 +322607030
    *z^72 +997380768*z^248 -10961366*z^276 -385369833*z^104
    +323*z^16 +27232379880*z^136 +4323330*z^48 -92190746241*
    z^196 -36708*z^308 -20609808196*z^220 +6816233581*z^232 -
    7780358999*z^228 -4209081*z^284 +59232895357*z^200 +
    49378215194*z^208 -30858791790*z^212 -51135748066*z^204 -11
    *z^348 +90553404712*z^192 +6265092815*z^96 +1578469*z^
    288 +33*z^344 +2091442392*z^240 +7072305*z^280 ;
    q := algsubs(z^4=x,q) ;
    coeftayl(p/q,x=0,n) ;
    end proc:
    seq(A237355(n),n=0..20) ;
Showing 1-2 of 2 results.