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 1-10 of 792 results. Next

A008137 Coordination sequence T1 for Zeolite Code LTA and RHO.

Original entry on oeis.org

1, 4, 9, 17, 28, 42, 60, 81, 105, 132, 162, 196, 233, 273, 316, 362, 412, 465, 521, 580, 642, 708, 777, 849, 924, 1002, 1084, 1169, 1257, 1348, 1442, 1540, 1641, 1745, 1852, 1962, 2076, 2193, 2313, 2436, 2562, 2692, 2825, 2961, 3100, 3242, 3388, 3537, 3689
Offset: 0

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Comments

Also, growth series for the affine Coxeter (or Weyl) groups B_3. - N. J. A. Sloane, Jan 11 2016
Also, coordination sequence for "rho" 3D uniform tiling. - N. J. A. Sloane, Feb 10 2018

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).
  • B. Grünbaum, Uniform tilings of 3-space, Geombinatorics, 4 (1994), 49-56. See tilings #25 and 27.
  • W. M. Meier, D. H. Olson and Ch. Baerlocher, Atlas of Zeolite Structure Types, 4th Ed., Elsevier, 1996.

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.
For partial sums see A299276.
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.

Programs

  • Maple
    (1-x^2)*(1-x^4)*(1-x^6)/((1-x)^4*(1-x^3)*(1-x^5));
    seq(coeff(series(%,x,n+1),x,n), n=0..48);

Formula

a(5*m+k) = 40*m^2 + 16*k*m + one of 5 numbers depending on k, 0 <= k < 5 (N. J. A. Sloane).
G.f.: (1-x^2)*(1-x^4)*(1-x^6)/((1-x)^4*(1-x^3)*(1-x^5)). This can also be written as (x+1)^3*(x^2+1)*(x^2-x+1)/((1-x)^3*(x^4+x^3+x^2+x+1)). - N. J. A. Sloane, Feb 10 2018
a(n) = 12/5 - 0^n + (8/5)*n^2 - (1/25)*(5+sqrt(5))*cos(2*Pi*n/5) - (1/25)*(5-sqrt(5))*cos(4*Pi*n/5). - Eric Simon Jacob, Feb 12 2023

A008253 Coordination sequence for diamond.

Original entry on oeis.org

1, 4, 12, 24, 42, 64, 92, 124, 162, 204, 252, 304, 362, 424, 492, 564, 642, 724, 812, 904, 1002, 1104, 1212, 1324, 1442, 1564, 1692, 1824, 1962, 2104, 2252, 2404, 2562, 2724, 2892, 3064, 3242, 3424, 3612, 3804, 4002, 4204, 4412, 4624, 4842, 5064, 5292, 5524
Offset: 0

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References

  • Inorganic Crystal Structure Database: Collection Code 9327.

Crossrefs

Programs

  • Mathematica
    {1}~Join~Table[2 (2 + Sum[Floor[(5 k + 3)/2], {k, n - 1}]), {n, 50}] (* Alexander Adamchuk, May 23 2006, edited by Michael De Vlieger, May 31 2022 *)
  • PARI
    Vec((1 + 2*x + 4*x^2 + 2*x^3 + x^4) / ((1 - x)^3*(1 + x)) + O(x^60)) \\ Colin Barker, Mar 21 2017

Formula

G.f.: (1 + 2*x + 4*x^2 + 2*x^3 + x^4) / ((1 - x)^3*(1 + x)).
a(2*m) = 10*m^2+2, a(2*m+1) = 10*m^2+10*m+4 (N. J. A. Sloane).
Apart from first term, first differences of A007904(n). - Alexander Adamchuk, May 23 2006
a(n) = 2* ( 2 + Sum_{k=1..n-1} floor((5*k+3)/2) ). - Alexander Adamchuk, May 23 2006
From Colin Barker, Mar 21 2017: (Start)
a(n) = (5*n^2 + 4)/2 for n>0 and even.
a(n) = (5*n^2 + 3)/2 for n odd.
a(n) = 2*a(n-1) - 2*a(n-3) + a(n-4) for n>4.
(End)

A008084 Coordination sequence T1 for Zeolite Code ACO, ASV, EDI, and THO.

Original entry on oeis.org

1, 4, 9, 19, 35, 52, 72, 100, 131, 163, 201, 244, 290, 340, 393, 451, 515, 580, 648, 724, 803, 883, 969, 1060, 1154, 1252, 1353, 1459, 1571, 1684, 1800, 1924, 2051, 2179, 2313, 2452, 2594, 2740, 2889, 3043, 3203, 3364, 3528, 3700, 3875, 4051, 4233, 4420
Offset: 0

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References

  • W. M. Meier, D. H. Olson, and Ch. Baerlocher, Atlas of Zeolite Structure Types, 4th Ed., Elsevier, 1996.

Programs

  • Mathematica
    CoefficientList[Series[-(x + 1)^3 (x^4 - x^3 + 3 x^2 - x + 1)/((x - 1)^3 (x^2 + 1) (x^2 + x + 1)), {x, 0, 50}], x] (* Vincenzo Librandi, Oct 15 2013 *)

Formula

For n > 1, a(n) = 2n^2 - 4n + 4 + p(n), with the 12-periodic sequence p(n) with period {0, 0, 0, -1, -1, 1, 0, -2, 0, 1, -1, -1}.
a(12*m+k) = 288*m^2 + 48*k*m + [ 2, 4, 9, 19, 35, 52, 72, 100, 131, 163, 201, 244 ], 0 <= k < 12. - N. J. A. Sloane
G.f.: -(x+1)^3*(x^4-x^3+3*x^2-x+1) / ((x-1)^3*(x^2+1)*(x^2+x+1)). - Colin Barker, Dec 12 2012

A008264 Coordination sequence for tridymite, lonsdaleite, and wurtzite.

Original entry on oeis.org

1, 4, 12, 25, 44, 67, 96, 130, 170, 214, 264, 319, 380, 445, 516, 592, 674, 760, 852, 949, 1052, 1159, 1272, 1390, 1514, 1642, 1776, 1915, 2060, 2209, 2364, 2524, 2690, 2860, 3036, 3217, 3404, 3595, 3792, 3994, 4202, 4414, 4632, 4855, 5084, 5317, 5556, 5800
Offset: 0

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References

  • Inorganic Crystal Structure Database: Collection Code 29343
  • Michael O'Keeffe, Topological and geometrical characterization of sites in silicon carbide polytypes, Chemistry of Materials 3 (2) (1991), 332-335. (Eq. (2) gives an empirical formula for a(n). - N. J. A. Sloane, Apr 07 2018)

Crossrefs

Cf. A008524 for 4-D analog, A008253 for diamond.
Cf. A217511 for theta series.

Programs

  • Mathematica
    a[n_] := (m = Quotient[n, 4]; k = Mod[n, 4]; 42*m^2 + 21*k*m + Switch[k, 0, 2, 1, 4, 2, 12, 3, 25]); a[0]=1; Table[a[n], {n, 0, 47}] (* Jean-François Alcover, Oct 11 2012, from the first formula *)
    Join[{1}, Table[1 + (42 n^2 + (1 + (-1)^n) (3 + 2 (-1)^((n - 1) n/2)) + 6)/16, {n, 50}]] (* Bruno Berselli, Jul 24 2013 *)
    LinearRecurrence[{2,-1,0,1,-2,1},{1,4,12,25,44,67,96},20] (* Harvey P. Dale, Dec 27 2016 *)
  • PARI
    a(n)=if(n, 1+(42*n^2+(1+(-1)^n)*(3+2*(-1)^((n-1)*n/2))+6)/16, 1) \\ Charles R Greathouse IV, Feb 10 2017

Formula

a(4*m+k) = 42*m^2 + 21*k*m + [ 2, 4, 12, 25 ], 0 <= k < 4 (N. J. A. Sloane).
a(n) = 1 + (42*n^2 + (1 + (-1)^n)*(3 + 2*(-1)^((n - 1)*n/2)) + 6)/16 for n > 0, a(0) = 1. - Bruno Berselli, Jul 24 2013
G.f.: (1 + 2*x + 5*x^2 + 5*x^3 + 5*x^4 + 2*x^5 + x^6)/((1 - x)^3*(1 + x + x^2 + x^3)). - Bruno Berselli, Jul 24 2013

A019456 Coordination sequence T1 for Zeolite Code CZP.

Original entry on oeis.org

1, 4, 9, 18, 32, 54, 83, 113, 149, 191, 234, 281, 342, 399, 459, 537, 611, 678, 763, 861, 947, 1035, 1151, 1267, 1367, 1481, 1611, 1738, 1862, 1995, 2140, 2291, 2443, 2591, 2751, 2929, 3094, 3252, 3439, 3639, 3816, 3995, 4211, 4427, 4618, 4823, 5055
Offset: 0

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References

  • W. M. Meier, D. H. Olson and Ch. Baerlocher, Atlas of Zeolite Structure Types, 4th Ed., Elsevier, 1996

Crossrefs

A019457 Coordination sequence T2 for Zeolite Code CZP.

Original entry on oeis.org

1, 4, 10, 20, 33, 56, 85, 114, 144, 192, 242, 280, 333, 412, 475, 526, 602, 698, 776, 850, 949, 1058, 1157, 1258, 1372, 1500, 1620, 1732, 1863, 2020, 2161, 2280, 2434, 2624, 2778, 2910, 3087, 3294, 3463, 3618, 3818, 4038, 4228, 4410, 4625, 4864, 5075
Offset: 0

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References

  • W. M. Meier, D. H. Olson and Ch. Baerlocher, Atlas of Zeolite Structure Types, 4th Ed., Elsevier, 1996

Crossrefs

A019458 Coordination sequence T3 for Zeolite Code CZP.

Original entry on oeis.org

1, 4, 8, 16, 33, 52, 73, 112, 160, 190, 214, 282, 351, 386, 439, 548, 624, 658, 742, 872, 953, 1012, 1127, 1276, 1380, 1462, 1582, 1744, 1877, 1970, 2101, 2302, 2464, 2558, 2710, 2948, 3113, 3210, 3397, 3660, 3834, 3952, 4166, 4444, 4637, 4782, 5005
Offset: 0

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References

  • W. M. Meier, D. H. Olson and Ch. Baerlocher, Atlas of Zeolite Structure Types, 4th Ed., Elsevier, 1996

Crossrefs

A033616 Coordination sequence T1 for Zeolite Code TSC.

Original entry on oeis.org

1, 4, 9, 16, 25, 37, 53, 74, 99, 125, 151, 177, 205, 238, 279, 328, 381, 434, 483, 528, 574, 627, 690, 762, 840, 919, 995, 1068, 1140, 1214, 1294, 1382, 1477, 1577, 1681, 1787, 1892, 1995, 2096, 2197, 2303, 2419, 2546, 2681, 2819, 2954, 3082, 3205, 3329
Offset: 0

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Comments

First 127 terms computed by Davide M. Proserpio using ToposPro.

Crossrefs

Cf. A033617 (second type), A299902 (partial sums).

Formula

G.f.: (1 + x)^3 * (1 + x^2) * (1 - x + 2*x^2 - x^3 + 3*x^4 - x^5 + 4*x^6 - x^7 + 4*x^8 - x^9 + 4*x^10 - x^11 + 4*x^12 - x^13 + 3*x^14 - x^15 + 2*x^16 - x^17 + x^18) / ((1 - x)^3 * (1 - x + x^2 - x^3 + x^4) * (1 + x + x^2 + x^3 + x^4) * (1 + x^3 + x^6) * (1 + x + x^2 + x^3 + x^4 + x^5 + x^6)). - Colin Barker, Dec 19 2015
From N. J. A. Sloane, Feb 22 2018 (Start)
The following is a another conjectured recurrence, found by gfun, using the command rec:=gfun[listtorec](t1, a(n)); (where t1 is a list of the initial terms) suggested by Paul Zimmermann.
Note: this should not be used to extend the sequence.
0 = (-38*n^3-836*n^2-5351*n)*a(n)+(-76*n^2-798*n)*a(n+1)+(-38*n^3-912*n^2-6149*n)*a(n+2)+(-38*n^3-988*n^2-6947*n)*a(n+3)+(-38*n^3-1064*n^2-7745*n)*a(n+4)+(-38*n^3-1140*n^2 -8543*n)*a(n+5)+(-76*n^3-2052*n^2-14692*n)*a(n+6)
+ (-532*n^2-5586*n)*a(n+7)+(-76*n^3-2204*n^2-16288*n)*a(n+8)+(-684*n^2-7182*n)*a(n+9)+(-684*n^2 -7182*n)*a(n+10)+(-684*n^2-7182*n)*a(n+11)+(-684*n^2-7182*n)*a(n+12)+(76*n^3+ 988*n^2+3520*n)*a(n+13)+(-532*n^2-5586*n)*a(n+14)+(76*n^3+1140*n^2+5116*n)*a(n+15)
+ (38*n^3+456*n^2+1361*n)*a(n+16)+(38*n^3+532*n^2+2159*n)*a(n+17)+(38*n^3+608*n^2+2957*n)*a(n+18)+(38*n^3+684*n^2+3755*n)*a(n+19)+(-76*n^2-798*n)*a(n+20)+(38*n^3+760*n^2+4553*n)*a(n+21), with
a(0) = 1, a(1) = 4, a(2) = 9, a(3) = 16, a(4) = 25, a(5) = 37, a(6) = 53, a(7) = 74, a(8) = 99, a(9) = 125, a(10) = 151, a(11) = 177, a(12) = 205, a(13) = 238, a(14) = 279, a(15) = 328, a(16) = 381, a(17) = 434, a(18) = 483, a(19) = 528, a(20) = 574, a(21) = 627
(End)

A033617 Coordination sequence T2 for Zeolite Code TSC.

Original entry on oeis.org

1, 4, 9, 17, 28, 41, 56, 73, 93, 117, 146, 180, 216, 253, 291, 329, 369, 414, 466, 524, 586, 650, 712, 773, 836, 902, 973, 1051, 1136, 1224, 1313, 1403, 1492, 1581, 1673, 1769, 1870, 1978, 2093, 2211, 2329, 2447, 2563, 2678, 2797, 2923, 3057, 3198, 3344
Offset: 0

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Author

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Comments

First 127 terms computed by Davide M. Proserpio using ToposPro.

Crossrefs

Cf. A033616, A299903 (partial sums).

Formula

G.f.: (1 + x)^3 * (1 - x + x^2) * (1 + x^2) * (1 + x^2 + x^3 + x^4 + x^5 + 2*x^6 + x^7 + 3*x^8 + x^9 + 2*x^10 + x^11 + x^12 + x^13 + x^14 + x^16) / ((1 - x)^3 * (1 - x + x^2 - x^3 + x^4) * (1 + x + x^2 + x^3 + x^4) * (1 + x^3 + x^6) * (1 + x + x^2 + x^3 + x^4 + x^5 + x^6)). - Colin Barker, Dec 20 2015
From N. J. A. Sloane, Feb 22 2018 (Start)
The following is another conjectured recurrence, found by gfun, using the command rec:=gfun[listtorec](t1, a(n)); (where t1 is a list of the initial terms) suggested by Paul Zimmermann.
Note: this should not be used to extend the sequence.
0 = (-38*n^3-836*n^2-5367*n)*a(n)+(-76*n^2-798*n)*a(n+1)+(-38*n^3-912*n^2-6165*n)*a(n+2)+(-38*n^3-988*n^2-6963*n)*a(n+3)+(-38*n^3-1064*n^2-7761*n)*a(n+4)+(-38*n^3-1140*n^2-8559*n)*a(n+5)+(-76*n^3-2052*n^2-14724*n)*a(n+6)
+ (-532*n^2-5586*n)*a(n+7)+(-76*n^3-2204*n^2-16320*n)*a(n+8)+(-684*n^2-7182*n)*a(n+9)+(-684*n^2-7182*n)*a(n+10)+(-684*n^2-7182*n)*a(n+11)+(-684*n^2-7182*n)*a(n+12)+(76*n^3+988*n^2+3552*n)*a(n+13)+(-532*n^2-5586*n)*a(n+14)
+ (76*n^3+1140*n^2+5148*n)*a(n+15)+(38*n^3+456*n^2+1377*n)*a(n+16)+(38*n^3+532*n^2+2175*n)*a(n+17)+(38*n^3+608*n^2+2973*n)*a(n+18)
+ (38*n^3+684*n^2+3771*n)*a(n+19)+(-76*n^2-798*n)*a(n+20)+(38*n^3+760*n^2+4569*n)*a(n+21), with
a(0) = 1, a(1) = 4, a(2) = 9, a(3) = 17, a(4) = 28, a(5) = 41, a(6) = 56, a(7) = 73, a(8) = 93, a(9) = 117, a(10) = 146, a(11) = 180, a(12) = 216, a(13) = 253, a(14) = 291, a(15) = 329, a(16) = 369, a(17) = 414, a(18) = 466, a(19) = 524, a(20) = 586, a(21) = 650.
(End)

A008016 Coordination sequence T2 for Zeolite Code AFO.

Original entry on oeis.org

1, 4, 11, 22, 41, 65, 88, 111, 145, 186, 231, 281, 336, 395, 455, 518, 597, 679, 752, 827, 921, 1024, 1123, 1222, 1330, 1442, 1555, 1678, 1821, 1965, 2088, 2207, 2357, 2518, 2671, 2829, 2996, 3167, 3335, 3506, 3705, 3903, 4072, 4247, 4461, 4688, 4899, 5104
Offset: 0

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Author

Keywords

References

  • W. M. Meier, D. H. Olson and Ch. Baerlocher, Atlas of Zeolite Structure Types, 4th Ed., Elsevier, 1996
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