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 61-70 of 70 results.

A242941 a(n) is the number of convex uniform tessellations in dimension n.

Original entry on oeis.org

1, 11, 28, 143
Offset: 1

Views

Author

Felix Fröhlich, May 27 2014

Keywords

Comments

Terms for n > 4 have not been determined so far. Alfredo Andreini in 1905 gave a value of 25 for a(3), later found to be incorrect. The value 28 for a(3) was given by Norman Johnson in 1991 and later in 1994 independently by Branko Grünbaum. The value for a(4) was given by George Olshevsky in 2006.
Deza and Shtogrin (2000) agree that the value of a(3) is 28, although the authors do not provide a proof. - Felix Fröhlich, Nov 29 2014
From Felix Fröhlich, Feb 03 2019: (Start)
The 11 convex uniform tilings are all illustrated in Kepler, 1619. For an argument that exactly 11 such tilings exist, see Grünbaum, Shephard, 1977.
In dimension 2, the definition of "uniform polytope" usually seems to be equivalent to the regular polygons in order to exclude polygons that alternate two different edge-lengths. Applying this principle retroactively to dimension 1 (as done, as I assume, by Coxeter, see Coxeter, 1973, p. 129) yields a(1) = 1. (End)

References

  • H. S. M. Coxeter, Regular Polytopes, Third Edition, Dover Publications, 1973, ISBN 9780486614809.
  • B. Grünbaum, Uniform tilings of 3-space, Geombinatorics, Vol. 4, No. 2 (1994), 49-56.
  • N. W. Johnson, Uniform Polytopes, [To appear, cf. Weiss, Stehle, 2017].

Crossrefs

Cf. A068599.
List of coordination sequences for the 11 uniform 2D tilings: A008458(the planar net 3.3.3.3.3.3), A008486 (6^3), A008574 (4.4.4.4 and 3.4.6.4), A008576 (4.8.8), A008579 (3.6.3.6), A008706(3.3.3.4.4), A072154 (4.6.12), A219529 (3.3.4.3.4), A250120(3.3.3.3.6), A250122 (3.12.12).
List of coordination sequences for the 28 uniform 3D tilings: cab: A299266, A299267; crs: A299268, A299269; fcu: A005901, A005902; fee: A299259, A299265; flu-e: A299272, A299273; fst: A299258, A299264; hal: A299274, A299275; hcp: A007899, A007202; hex: A005897, A005898; kag: A299256, A299262; lta: A008137, A299276; pcu: A005899, A001845; pcu-i: A299277, A299278; reo: A299279, A299280; reo-e: A299281, A299282; rho: A008137, A299276; sod: A005893, A005894; sve: A299255, A299261; svh: A299283, A299284; svj: A299254, A299260; svk: A010001, A063489; tca: A299285, A299286; tcd: A299287, A299288; tfs: A005899, A001845; tsi: A299289, A299290; ttw: A299257, A299263; ubt: A299291, A299292; bnn: A007899, A007202. See the Proserpio link in A299266 for overview.

Extensions

Edited by N. J. A. Sloane, Feb 15 2018
Edited by Felix Fröhlich, Feb 03-10 2019

A267168 Growth series for affine Coxeter group B_5.

Original entry on oeis.org

1, 6, 20, 51, 110, 211, 372, 615, 966, 1455, 2117, 2991, 4120, 5551, 7334, 9524, 12180, 15365, 19146, 23594, 28784, 34795, 41711, 49619, 58611, 68783, 80234, 93067, 107389, 123312, 140952, 160430, 181870, 205400, 231152, 259261, 289867, 323114, 359151, 398131, 440211, 485551, 534315, 586672, 642794, 702858, 767045, 835540, 908532, 986214
Offset: 0

Views

Author

N. J. A. Sloane, Jan 11 2016

Keywords

References

  • N. Bourbaki, Groupes et Algèbres de Lie, Chap. 4, 5 and 6, Hermann, Paris, 1968. See Chap. VI, Section 4, Problem 10b, page 231, W_a(t).

Crossrefs

The growth series for the finite Coxeter (or Weyl) groups B_2 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Formula

The growth series for the affine Coxeter group of type B_k (k >= 2) has g.f. = Product_i (1-x^{m_i+1})/((1-x)*(1-x^{m_i})) where the m_i are [1,3,5,...,2k-1].
Here (k=5) the G.f. is -(1+t)*(1+t+t^2+t^3)*(t^3+1)*(1+t+t^2+t^3+t^4+t^5+t^6+t^7)*(t^5+1)/(-1+t^9)/(-1+t^7)/(-1+t)^3.

A267169 Growth series for affine Coxeter group B_6.

Original entry on oeis.org

1, 7, 27, 78, 188, 399, 771, 1386, 2352, 3807, 5924, 8916, 13041, 18606, 25971, 35554, 47835, 63361, 82750, 106695, 135968, 171425, 214011, 264764, 324820, 395417, 477900, 573724, 684459, 811795, 957546, 1123655, 1312198, 1525389, 1765583, 2035281, 2337134, 2673948, 3048689, 3464488, 3924646, 4432636, 4992108, 5606893, 6281008, 7018660
Offset: 0

Views

Author

N. J. A. Sloane, Jan 11 2016

Keywords

References

  • N. Bourbaki, Groupes et Algèbres de Lie, Chap. 4, 5 and 6, Hermann, Paris, 1968. See Chap. VI, Section 4, Problem 10b, page 231, W_a(t).

Crossrefs

The growth series for the finite Coxeter (or Weyl) groups B_2 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Formula

The growth series for the affine Coxeter group of type B_k (k >= 2) has g.f. = Product_i (1-x^{m_i+1})/((1-x)*(1-x^{m_i})) where the m_i are [1,3,5,...,2k-1].

A267170 Growth series for affine Coxeter group B_7.

Original entry on oeis.org

1, 8, 35, 113, 301, 700, 1471, 2857, 5209, 9016, 14940, 23856, 36897, 55504, 81481, 117055, 164941, 228412, 311373, 418440, 555023, 727414, 942880, 1209761, 1537573, 1937115, 2420581, 3001676, 3695738, 4519865, 5493047, 6636302, 7972817, 9528094, 11330100, 13409422, 15799426, 18536422, 21659833, 25212370, 29240211, 33793185, 38924961
Offset: 0

Views

Author

N. J. A. Sloane, Jan 11 2016

Keywords

References

  • N. Bourbaki, Groupes et Algèbres de Lie, Chap. 4, 5 and 6, Hermann, Paris, 1968. See Chap. VI, Section 4, Problem 10b, page 231, W_a(t).

Crossrefs

The growth series for the finite Coxeter (or Weyl) groups B_2 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Formula

The growth series for the affine Coxeter group of type B_k (k >= 2) has g.f. = Product_i (1-x^{m_i+1})/((1-x)*(1-x^{m_i})) where the m_i are [1,3,5,...,2k-1].

A267171 Growth series for affine Coxeter group B_8.

Original entry on oeis.org

1, 9, 44, 157, 458, 1158, 2629, 5486, 10695, 19711, 34651, 58507, 95404, 150908, 232389, 349445, 514393, 742832, 1054283, 1472911, 2028333, 2756518, 3700784, 4912897, 6454277, 8397316, 10826813, 13841530, 17555875, 22101717, 27630339, 34314534, 42350849, 51961982, 63399337, 76945741, 92918329, 111671603, 133600669, 159144658, 188790335
Offset: 0

Views

Author

N. J. A. Sloane, Jan 11 2016

Keywords

References

  • N. Bourbaki, Groupes et Algèbres de Lie, Chap. 4, 5 and 6, Hermann, Paris, 1968. See Chap. VI, Section 4, Problem 10b, page 231, W_a(t).

Crossrefs

The growth series for the finite Coxeter (or Weyl) groups B_2 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Formula

The growth series for the affine Coxeter group of type B_k (k >= 2) has g.f. = Product_i (1-x^{m_i+1})/((1-x)*(1-x^{m_i})) where the m_i are [1,3,5,...,2k-1].

A267172 Growth series for affine Coxeter group B_9.

Original entry on oeis.org

1, 10, 54, 211, 669, 1827, 4456, 9942, 20637, 40348, 74999, 133506, 228910, 379818, 612207, 961652, 1476045, 2218878, 3273169, 4746115, 6774561, 9531380, 13232864, 18147232, 24604366, 33006891, 43842720, 57699190, 75278921, 97417535, 125103378, 159499393, 201967298, 254094228, 317722005, 394979205, 488316197, 600543335, 734872490
Offset: 0

Views

Author

N. J. A. Sloane, Jan 11 2016

Keywords

References

  • N. Bourbaki, Groupes et Algèbres de Lie, Chap. 4, 5 and 6, Hermann, Paris, 1968. See Chap. VI, Section 4, Problem 10b, page 231, W_a(t).

Crossrefs

The growth series for the finite Coxeter (or Weyl) groups B_2 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Formula

The growth series for the affine Coxeter group of type B_k (k >= 2) has g.f. = Product_i (1-x^{m_i+1})/((1-x)*(1-x^{m_i})) where the m_i are [1,3,5,...,2k-1].

A267173 Growth series for affine Coxeter group B_10.

Original entry on oeis.org

1, 11, 65, 276, 945, 2772, 7228, 17170, 37807, 78155, 153154, 286660, 515570, 895388, 1507595, 2469247, 3945292, 6164170, 9437339, 14183455, 20958025, 30489449, 43722470, 61870160, 86475684, 119485204, 163333410, 221043295, 296341927, 393794113, 518955998, 678550795, 880669001, 1134995618, 1453067068, 1848560666, 2337619696, 2939217322
Offset: 0

Views

Author

N. J. A. Sloane, Jan 11 2016

Keywords

References

  • N. Bourbaki, Groupes et Algèbres de Lie, Chap. 4, 5 and 6, Hermann, Paris, 1968. See Chap. VI, Section 4, Problem 10b, page 231, W_a(t).

Crossrefs

The growth series for the finite Coxeter (or Weyl) groups B_2 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Formula

The growth series for the affine Coxeter group of type B_k (k >= 2) has g.f. = Product_i (1-x^{m_i+1})/((1-x)*(1-x^{m_i})) where the m_i are [1,3,5,...,2k-1].

A267174 Growth series for affine Coxeter group B_11.

Original entry on oeis.org

1, 12, 77, 353, 1298, 4070, 11298, 28468, 66275, 144430, 297584, 584244, 1099814, 1995202, 3502797, 5972044, 9917336, 16081506, 25518845, 39702300, 60660325, 91149775, 134872255, 196742469, 283218364, 402704237, 566039474, 787087225, 1083439094, 1477253844, 1996250190, 2674875984, 3555678491, 4690903019, 6144349905, 7993522778
Offset: 0

Views

Author

N. J. A. Sloane, Jan 11 2016

Keywords

References

  • N. Bourbaki, Groupes et Algèbres de Lie, Chap. 4, 5 and 6, Hermann, Paris, 1968. See Chap. VI, Section 4, Problem 10b, page 231, W_a(t).

Crossrefs

The growth series for the finite Coxeter (or Weyl) groups B_2 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Formula

The growth series for the affine Coxeter group of type B_k (k >= 2) has g.f. = Product_i (1-x^{m_i+1})/((1-x)*(1-x^{m_i})) where the m_i are [1,3,5,...,2k-1].

A161697 Number of reduced words of length n in the Weyl group B_4.

Original entry on oeis.org

1, 4, 9, 16, 24, 32, 39, 44, 46, 44, 39, 32, 24, 16, 9, 4, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Nov 30 2009

Keywords

Comments

Computed with MAGMA using commands similar to those used to compute A161409.

References

  • J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial.
  • N. Bourbaki, Groupes et algèbres de Lie, Chap. 4, 5, 6. (The group is defined in Planche II.)

Crossrefs

The growth series for the finite Coxeter (or Weyl) groups B_2 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Programs

  • Magma
    m:=17; R:=PowerSeriesRing(Integers(), m); Coefficients(R!((&*[1-t^(2*k): k in [1..4]])/(1-t)^4)); // G. C. Greubel, Oct 25 2018
  • Maple
    seq(coeff(series(mul((1-x^(2k))/(1-x),k=1..4),x,n+1), x, n), n = 0 .. 100); # Muniru A Asiru, Oct 25 2018
  • Mathematica
    CoefficientList[Series[Product[(1-x^(2*k)), {k,1,4}] /(1-x)^4, {x,0,16}], x] (* G. C. Greubel, Oct 25 2018 *)
  • PARI
    t='t+O('t^17); Vec(prod(k=1,4,1-t^(2*k))/(1-t)^4) \\ G. C. Greubel, Oct 25 2018
    

Formula

G.f. for B_m is the polynomial Prod_{k=1..m}(1-x^(2k))/(1-x). Only finitely many terms are nonzero. This is a row of the triangle in A128084.

A161698 Number of reduced words of length n in the Weyl group B_5.

Original entry on oeis.org

1, 5, 14, 30, 54, 86, 125, 169, 215, 259, 297, 325, 340, 340, 325, 297, 259, 215, 169, 125, 86, 54, 30, 14, 5, 1
Offset: 0

Views

Author

John Cannon and N. J. A. Sloane, Nov 30 2009

Keywords

Comments

Computed with MAGMA using commands similar to those used to compute A161409.

References

  • J. E. Humphreys, Reflection Groups and Coxeter Groups, Cambridge, 1990. See under Poincaré polynomial.
  • N. Bourbaki, Groupes et algèbres. de Lie, Chap. 4, 5, 6. (The group is defined in Planche II.)

Crossrefs

The growth series for the finite Coxeter (or Weyl) groups B_2 through B_12 are A161696-A161699, A161716, A161717, A161733, A161755, A161776, A161858. These are all rows of A128084. The growth series for the affine Coxeter (or Weyl) groups B_2 through B_12 are A008576, A008137, A267167-A267175.

Programs

  • Magma
    m:=26; R:=PowerSeriesRing(Integers(), m); Coefficients(R!((&*[1-t^(2*k): k in [1..5]])/(1-t)^5)); // G. C. Greubel, Oct 25 2018
  • Maple
    seq(coeff(series(mul((1-x^(2*k))/(1-x),k=1..5),x,n+1), x, n), n = 0 .. 25); # Muniru A Asiru, Oct 25 2018
  • Mathematica
    CoefficientList[Series[Product[(1-x^(2*k)), {k,1,5}] /(1-x)^5, {x,0,25}], x] (* G. C. Greubel, Oct 25 2018 *)
  • PARI
    t='t+O('t^26); Vec(prod(k=1,5,1-t^(2*k))/(1-t)^5) \\ G. C. Greubel, Oct 25 2018
    

Formula

G.f. for B_m is the polynomial Prod_{k=1..m}(1-x^(2k))/(1-x). Only finitely many terms are nonzero. This is a row of the triangle in A128084.
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