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 1-5 of 5 results.

A233308 Number A(n,k) of tilings of a k X k X n box using k*n bricks of shape k X 1 X 1; square array A(n,k), n>=0, k>=1, read by antidiagonals.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 2, 9, 1, 1, 2, 4, 32, 1, 1, 2, 4, 21, 121, 1, 1, 2, 4, 8, 92, 450, 1, 1, 2, 4, 8, 45, 320, 1681, 1, 1, 2, 4, 8, 16, 248, 1213, 6272, 1, 1, 2, 4, 8, 16, 93, 1032, 4822, 23409, 1, 1, 2, 4, 8, 16, 32, 668, 3524, 18556, 87362, 1, 1, 2, 4, 8, 16, 32, 189, 3440, 13173, 70929, 326041, 1
Offset: 0

Views

Author

Alois P. Heinz, Dec 07 2013

Keywords

Examples

			Square array A(n,k) begins:
  1,     1,     1,     1,     1,     1, ...
  1,     2,     2,     2,     2,     2, ...
  1,     9,     4,     4,     4,     4, ...
  1,    32,    21,     8,     8,     8, ...
  1,   121,    92,    45,    16,    16, ...
  1,   450,   320,   248,    93,    32, ...
  1,  1681,  1213,  1032,   668,   189, ...
  1,  6272,  4822,  3524,  3440,  1832, ...
  1, 23409, 18556, 13173, 13728, 11976, ...
		

Crossrefs

Columns k=1-6 give: A000012, A006253, A233289, A233291, A233294, A233424.
Diagonals include: A000079, A068156.

Programs

  • Maple
    b:= proc(n, l) option remember; local d, t, k; d:= isqrt(nops(l));
          if max(l[])>n then 0 elif n=0 then 1
        elif min(l[])>0 then t:=min(l[]); b(n-t, map(x->x-t, l))
        else for k while l[k]>0 do od; b(n, subsop(k=d, l))+
             `if`(irem(k,d)=1 and {seq(l[k+j], j=1..d-1)}={0},
             b(n, [seq(`if`(h-k=0, 1, l[h]), h=1..nops(l))]), 0)+
             `if`(k<=d and {seq(l[k+d*j], j=1..d-1)}={0},
             b(n, [seq(`if`(irem(h-k, d)=0, 1, l[h]), h=1..nops(l))]), 0)
          fi
        end:
    A:= (n, k)-> `if`(k>n, 2^n, b(n, [0$k^2])):
    seq(seq(A(n, 1+d-n), n=0..d), d=0..11);
  • Mathematica
    b[n_, l_] := b[n, l] = Module[{d, t, k}, d= Sqrt[Length[l]]; Which[ Max[l]>n, 0, n==0, 1, Min[l]>0, t=Min[l]; b[n-t, l-t], True, k=Position[l, 0, 1][[1, 1]]; b[n, ReplacePart[l, k->d]]+ If[Mod[k, d]==1 && Union[ Table[ l[[k+j]], {j, 1, d-1}]] == {0}, b[n, Table[ If [h-k=0, 1, l[[h]] ], {h, 1, Length[l]}]], 0]+ If[k <= d && Union[ Table[ l[[k+d*j]], {j, 1, d-1}]] == {0}, b[n, Table[ If[ Mod[h-k, d] == 0, 1, l[[h]] ], {h, 1, Length[l]}]], 0] ] ]; a[n_, k_]:= If[k>n, 2^n, b[n, Array[0&, k^2]]]; Table[Table[a[n, 1+d-n], {n, 0, d}], {d, 0, 11}] // Flatten (* Jean-François Alcover, Dec 13 2013, translated from Maple *)

Formula

A(n,k) = 2^n = A000079(n) for k>n.
A(n,n) = A068156(n) for n>1.

A233291 Number of tilings of a 4 X 4 X n box using 4n bricks of shape 4 X 1 X 1.

Original entry on oeis.org

1, 2, 4, 8, 45, 248, 1032, 3524, 13173, 54274, 228712, 917992, 3608665, 14286188, 57438652, 231343468, 926921081, 3700936774, 14793198332, 59241396140, 237333611629, 950127617692, 3801974385964, 15215432779936, 60907523900693, 243826775063490, 976008753961184
Offset: 0

Views

Author

Alois P. Heinz, Dec 06 2013

Keywords

Crossrefs

Column k=4 of A233308.

Formula

G.f.: (x^31 -x^30 -x^29 -3*x^28 -5*x^27 +8*x^26 +3*x^25 -39*x^24 +48*x^23 +34*x^22 -11*x^21 +112*x^20 -63*x^19 -34*x^18 +166*x^17 -188*x^16 -174*x^15 +151*x^14 -251*x^13 +57*x^12 +104*x^11 +171*x^10 -69*x^9 -90*x^8 -30*x^7 -61*x^6 +20*x^5 +31*x^4 +4*x^3 +4*x^2 +x -1) / (-x^35 +x^34 +x^33 +5*x^32 +4*x^31 -11*x^30 -10*x^29 +54*x^28 -65*x^27 -48*x^26 -48*x^25 -195*x^24 +231*x^23 -78*x^22 -473*x^21 +794*x^20 +447*x^19 -981*x^18 +1285*x^17 +395*x^16 -720*x^15 -202*x^14 +640*x^13 +567*x^12 -232*x^11 +638*x^10 -169*x^9 -233*x^8 -256*x^7 -97*x^6 +29*x^5 +52*x^4 -4*x^3 +2*x^2 +3*x -1).

A233294 Number of tilings of a 5 X 5 X n box using 5n bricks of shape 5 X 1 X 1.

Original entry on oeis.org

1, 2, 4, 8, 16, 93, 668, 3440, 13728, 46252, 172577, 739002, 3417464, 15550336, 65956764, 271247405, 1119519052, 4726308568, 20348072952, 87598217268, 373660404281, 1581318625634, 6680851858676, 28326586367464, 120536842633616, 513461699313993
Offset: 0

Views

Author

Alois P. Heinz, Dec 06 2013

Keywords

Crossrefs

Column k=5 of A233308.

Formula

G.f.: see link above.

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) ;

A273474 Number of tilings of a 3 X 5 X n box using 5n bricks of shape 3 X 1 X 1.

Original entry on oeis.org

1, 4, 16, 320, 4430, 40872, 463106, 5675188, 63422950, 710698093, 8200538232, 93691594514, 1063586983374, 12137123569004, 138570852491100, 1579149122960061, 18003479738145524, 205351456145093852, 2341614891431192875, 26699543185422994944, 304468247045695911612
Offset: 0

Views

Author

Alois P. Heinz, May 23 2016

Keywords

Crossrefs

Showing 1-5 of 5 results.