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.

User: Mira Shalah

Mira Shalah's wiki page.

Mira Shalah has authored 4 sequences.

A290868 a(n) is the number of fixed tree polycubes of size n that are proper in n-5 dimensions.

Original entry on oeis.org

0, 1, 568, 116004, 15998985, 1839569920, 194498568156, 19903875199488, 2028587719434848, 209368404017676288, 22100537701746000000, 2400300773277150740480, 269182253907724040230656, 31234215889947671471849472, 3753858472917234012947022848, 467486957946431078400000000000
Offset: 5

Author

Mira Shalah, Aug 12 2017

Keywords

Comments

Denoted DT(n,n-5).

Crossrefs

A290738 gives the total number of fixed n-cell polycubes (not necessarily trees) that are proper in n-5 dimensions.

Formula

a(n) = 2^(n-9)*n^(n-11)*(n-5)*(240*n^11 - 6480*n^10 + 73640*n^9 - 461232*n^8 + 1778615*n^7 - 4707195*n^6 + 11632070*n^5 - 41919528*n^4 + 158857920*n^3 - 483329520*n^2 + 1481660640*n - 2863123200)/360. (proved)

A290738 a(n) is the number of fixed polycubes of size n that are proper in n-5 dimensions.

Original entry on oeis.org

0, 1, 758, 154741, 20762073, 2323972976, 240154383596, 24109617950208, 2417940914461280, 246158020396388352, 25680108955640400000, 2760762217507260989440, 306854769192894226859776, 35326258772832011339956224, 4216066596599500902861091840, 521775392548443914240000000000
Offset: 5

Author

Mira Shalah, Aug 12 2017

Keywords

Comments

Denoted DX(n,n-5).

Crossrefs

A259015 gives the number of n-cell polycubes that are proper in n-4 dimensions.
Diagonal 5 of A195739.

Formula

a(n) = 2^(n-12)*n^(n-11)*(n-5)*(240*n^11 - 6000*n^10 + 62240*n^9 - 356232*n^8 + 1335320*n^7 - 4062240*n^6 + 12397445*n^5 - 42322743*n^4 + 150403080*n^3 - 535510740*n^2 + 1923269040*n - 3731495040)/45. (proved)

A259017 Number of fixed tree polycubes of size n that are proper in n-4 dimensions.

Original entry on oeis.org

0, 1, 172, 17041, 1382400, 104454120, 7801139200, 593322510704, 46672464052224, 3827977546598400, 328664453612830720, 29590252898580000000, 2794588822832496508928, 276747699113763664091136, 28712738456619366481920000, 3117500646133634877355274240, 353783948741967872000000000000
Offset: 4

Author

Mira Shalah, Jun 16 2015

Keywords

Crossrefs

A259015 gives the total number of fixed polycubes (not necessarily trees) proper in n-4 dimensions.

Programs

  • Magma
    [2^(n-7)*n^(n-9)*(n-4)*(8*n^8 - 140*n^7 + 1010*n^6 - 3913*n^5 + 9201*n^4 - 15662*n^3 + 34500*n^2 - 120552*n + 221760)/6: n in [4..20]]; // Vincenzo Librandi, Jun 20 2015
  • PARI
    a(n) = 2^(n-7) * n^(n-9) * (n-4) * (8*n^8-140*n^7+1010*n^6 -3913*n^5 +9201*n^4-15662*n^3+34500*n^2-120552*n +221760)/6 \\ Colin Barker, Jun 16 2015
    

Formula

a(n) = 2^(n-7)*n^(n-9)*(n-4)*(8*n^8 - 140*n^7 + 1010*n^6 - 3913*n^5 + 9201*n^4 - 15662*n^3 + 34500*n^2 - 120552*n + 221760)/6.

A259015 The number of fixed polycubes of size n that span n-4 dimensions.

Original entry on oeis.org

0, 1, 214, 21225, 1688424, 125055400, 9178531200, 687848686448, 53435249786880, 4336107249936384, 368887991492608000, 32948013484980000000, 3090086319932923969536, 304136142049322287011840, 31382704663810285705887744, 3390841628447041935421747200, 383124440688361472000000000000
Offset: 4

Author

Mira Shalah, Jun 16 2015

Keywords

References

  • G. Barequet, M. Shalah, Automatic Proofs for Formulae Enumerating Proper Polycubes, 31st International Symposium on Computational Geometry (SoCG’15). Editors: Lars Arge and János Pach; pp. 19-22, 2015.

Crossrefs

Diagonal 4 of A195739.

Programs

  • Magma
    [2^(n-7)*n^(n-9)*(n-4)*(8*n^8-128*n^7+828*n^6-2930*n^5 +7404*n^4-17523*n^3+41527*n^2-114302*n+204960)/6: n in [4..20]]; // Vincenzo Librandi, Jun 20 2015
  • Mathematica
    Table[2^(n - 7) n^(n - 9) (n - 4) (8 n^8 - 128 n^7 + 828 n^6 - 2930 n^5 + 7404 n^4 - 17523 n^3 + 41527 n^2 - 114302 n + 204960)/6, {n, 4, 20}] (* Michael De Vlieger, Jun 19 2015 *)
  • PARI
    a(n)=2^(n-7)*n^(n-9)*(n-4)*(8*n^8-128*n^7+828*n^6 -2930*n^5 +7404*n^4-17523*n^3 +41527*n^2-114302*n +204960)/6 \\ Charles R Greathouse IV, Jun 16 2015
    

Formula

a(n) = 2^(n-7)*n^(n-9)*(n-4)*(8*n^8 - 128*n^7 + 828*n^6 - 2930*n^5 + 7404*n^4 - 17523*n^3 + 41527*n^2 - 114302*n + 204960)/6.

Extensions

Typo in formula fixed by Colin Barker, Jun 16 2015