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.

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A182467 a(n) = 3a(n-1) - 2a(n-2) with a(0)=36 and a(1)=90.

Original entry on oeis.org

36, 90, 198, 414, 846, 1710, 3438, 6894, 13806, 27630, 55278, 110574, 221166, 442350, 884718, 1769454, 3538926, 7077870, 14155758, 28311534, 56623086, 113246190, 226492398, 452984814, 905969646, 1811939310, 3623878638, 7247757294, 14495514606, 28991029230
Offset: 0

Views

Author

Odimar Fabeny, Apr 30 2012

Keywords

Comments

Number of vertices into building blocks of 3d objects with 9 vertices.

Examples

			a(0) = 9+18+9;
a(1) = 9+18+36+18+9;
a(2) = 9+18+36+72+36+18+9;
a(3) = 9+18+36+72+144+72+36+18+9.
		

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{3,-2},{36,90},30] (* or *) CoefficientList[Series[(-18(x-2))/(1-3x+2x^2),{x,0,30}],x] (* Harvey P. Dale, Apr 29 2013 *)

Formula

a(n) = a(n-1)*2 + 18
G.f.: -((18*(x-2))/(2*x^2-3*x+1)). - Harvey P. Dale, Apr 29 2013
a(n) = 18*A153893(n). - Michel Marcus, Jun 01 2014

A175164 a(n) = 16*(2^n - 1).

Original entry on oeis.org

0, 16, 48, 112, 240, 496, 1008, 2032, 4080, 8176, 16368, 32752, 65520, 131056, 262128, 524272, 1048560, 2097136, 4194288, 8388592, 16777200, 33554416, 67108848, 134217712, 268435440
Offset: 0

Views

Author

Reinhard Zumkeller, Feb 28 2010

Keywords

Crossrefs

Sequences of the form m*(2^n - 1): A000225 (m=1), A000918 (m=2), A068156 (m=3), A028399 (m=4), A068293 (m=6), A159741 (m=8), this sequence (m=16), A175165 (m=32), A175166 (m=64).

Programs

  • Magma
    I:=[0,16]; [n le 2 select I[n] else 3*Self(n-1) - 2*Self(n-2): n in [1..41]]; // G. C. Greubel, Jul 08 2021
    
  • Mathematica
    16*(2^Range[0,40] - 1) (* G. C. Greubel, Jul 08 2021 *)
  • Python
    def A175164(n): return (1<Chai Wah Wu, Jun 27 2023
  • Sage
    [16*(2^n -1) for n in (0..40)] # G. C. Greubel, Jul 08 2021
    

Formula

a(n) = 2^(n+4) - 16.
a(n) = A173787(n+4, 4).
a(2*n) = A140504(n+2)*A028399(n).
a(n) = 3*a(n-1) - 2*a(n-2), a(0)=0, a(1)=16. - Vincenzo Librandi, Dec 28 2010
From G. C. Greubel, Jul 08 2021: (Start)
G.f.: 16*x/((1-x)*(1-2*x)).
E.g.f.: 16*(exp(2*x) - exp(x)). (End)

A175166 a(n) = 64*(2^n - 1).

Original entry on oeis.org

0, 64, 192, 448, 960, 1984, 4032, 8128, 16320, 32704, 65472, 131008, 262080, 524224, 1048512, 2097088, 4194240, 8388544, 16777152, 33554368, 67108800, 134217664, 268435392, 536870848, 1073741760
Offset: 0

Views

Author

Reinhard Zumkeller, Feb 28 2010

Keywords

Crossrefs

Sequences of the form m*(2^n - 1): A000225 (m=1), A000918 (m=2), A068156 (m=3), A028399 (m=4), A068293 (m=6), A159741 (m=8), A175164 (m=16), A175165 (m=32), this sequence (m=64).

Programs

  • Magma
    I:=[0,64]; [n le 2 select I[n] else 3*Self(n-1) - 2*Self(n-2): n in [1..41]]; // G. C. Greubel, Jul 08 2021
    
  • Mathematica
    LinearRecurrence[{3,-2},{0,64},30] (* Harvey P. Dale, Apr 08 2015 *)
  • Python
    def A175166(n): return (1<Chai Wah Wu, Jun 27 2023
  • Sage
    [64*(2^n -1) for n in (0..40)] # G. C. Greubel, Jul 08 2021
    

Formula

a(n) = 2^(n+6) - 64.
a(n) = A173787(n+6, 6).
a(2*n) = A175161(n)*A159741(n) for n > 0.
a(n) = 3*a(n-1) - 2*a(n-2), a(0)=0, a(1)=64. - Vincenzo Librandi, Dec 28 2010
From G. C. Greubel, Jul 08 2021: (Start)
G.f.: 64*x/((1-x)*(1-2*x)).
E.g.f.: 64*(exp(2*x) - exp(x)). (End)

A182461 a(n) = 3*a(n-1) - 2*a(n-2) with a(0)=16 and a(1)=40.

Original entry on oeis.org

16, 40, 88, 184, 376, 760, 1528, 3064, 6136, 12280, 24568, 49144, 98296, 196600, 393208, 786424, 1572856, 3145720, 6291448, 12582904, 25165816, 50331640, 100663288, 201326584, 402653176, 805306360, 1610612728, 3221225464, 6442450936, 12884901880
Offset: 0

Views

Author

Odimar Fabeny, Apr 30 2012

Keywords

Comments

Number of vertices into building blocks of 3d objects with 4 vertices.

Examples

			a(0) = 4+8+4;
a(1) = 4+8+16+8+4;
a(2) = 4+8+16+32+16+8+4;
a(3) = 4+8+16+32+64+32+16+8+4.
		

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[-((8 (x - 2))/(2 x^2 - 3 x + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 02 2014 *)

Formula

a(n) = a(n-1)*2 + 8.
G.f.: 16 + 40*x + 88*x^2 + 184*x^3 + 376*x^4 + 760*x^5 + 1528*x^6 + ...
a(n) = 8 * A055010(n+1). [Joerg Arndt, Jun 01 2014]
G.f.: -((8*(x - 2))/(2*x^2 - 3*x + 1)). - Vincenzo Librandi, Jun 02 2014

A182462 a(n) = 3a(n-1) - 2a(n-2) with a(0)=20 and a(1)=50.

Original entry on oeis.org

20, 50, 110, 230, 470, 950, 1910, 3830, 7670, 15350, 30710, 61430, 122870, 245750, 491510, 983030, 1966070, 3932150, 7864310, 15728630, 31457270, 62914550, 125829110, 251658230, 503316470, 1006632950, 2013265910, 4026531830, 8053063670, 16106127350
Offset: 0

Views

Author

Odimar Fabeny, Apr 30 2012

Keywords

Comments

Number of vertices into building blocks of 3d objects with 5 vertices.

Examples

			a(0) = 5+10+5;
a(1) = 5+10+20+10+5;
a(2) = 5+10+20+40+20+10+5;
a(3) = 5+10+20+40+80+40+20+10+5.
		

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[-((10 (x - 2))/(2 x^2 - 3 x + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 02 2014 *)

Formula

a(n) = a(n-1)*2 + 10.
a(n) = 10*A153893(n). - Michel Marcus, Jun 01 2014
G.f.: -((10*(x - 2))/(2*x^2 - 3*x + 1)). - Vincenzo Librandi, Jun 02 2014

A182465 a(n) = 3a(n-1) - 2a(n-2) with a(0)=28 and a(1)=70.

Original entry on oeis.org

28, 70, 154, 322, 658, 1330, 2674, 5362, 10738, 21490, 42994, 86002, 172018, 344050, 688114, 1376242, 2752498, 5505010, 11010034, 22020082, 44040178, 88080370, 176160754, 352321522, 704643058, 1409286130, 2818572274, 5637144562, 11274289138, 22548578290
Offset: 0

Views

Author

Odimar Fabeny, Apr 30 2012

Keywords

Comments

Number of vertices into building blocks of 3d objects with 7 vertices.

Examples

			a(0) = 7+14+7;
a(0) = 7+14+28+14+7;
a(0) = 7+14+28+56+28+14+7;
a(0) = 7+14+28+56+112+56+28+14+7.
		

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[-((14 (x - 2))/(2 x^2 - 3 x + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 01 2014 *)
    LinearRecurrence[{3,-2},{28,70},30] (* Harvey P. Dale, Oct 05 2015 *)

Formula

a(n) = a(n-1)*2 + 14.
a(n) = 14*A153893(n). - Michel Marcus, Jun 01 2014
G.f.: -((14*(x-2))/(2*x^2-3*x+1)). - Vincenzo Librandi, Jun 01 2014

A182466 a(n) = 3a(n-1) - 2a(n-2) with a(0)=32 and a(1)=80.

Original entry on oeis.org

32, 80, 176, 368, 752, 1520, 3056, 6128, 12272, 24560, 49136, 98288, 196592, 393200, 786416, 1572848, 3145712, 6291440, 12582896, 25165808, 50331632, 100663280, 201326576, 402653168, 805306352, 1610612720, 3221225456, 6442450928, 12884901872, 25769803760, 51539607536
Offset: 0

Views

Author

Odimar Fabeny, Apr 30 2012

Keywords

Comments

Number of vertices into building blocks of 3d objects with 8 vertices.

Examples

			a(0) = 8+16+8;
a(1) = 8+16+32+16+8;
a(2) = 8+16+32+64+32+16+8;
a(3) = 8+16+32+64+128+64+32+16+8.
		

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{3,-2},{32,80},40] (* or *) Table[8(3*2^n-2),{n,40}] (* Harvey P. Dale, Aug 23 2012 *)
    CoefficientList[Series[-((16 (x - 2))/(2 x^2 - 3 x + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Jun 02 2014 *)

Formula

a(n) = a(n-1)*2 + 16.
a(n) = 8*(3*2^n-2). - Harvey P. Dale, Aug 23 2012
G.f.: -((16(x-2))/(2*x^2-3*x+1)). - Harvey P. Dale, Aug 23 2012

A175165 a(n) = 32*(2^n - 1).

Original entry on oeis.org

0, 32, 96, 224, 480, 992, 2016, 4064, 8160, 16352, 32736, 65504, 131040, 262112, 524256, 1048544, 2097120, 4194272, 8388576, 16777184, 33554400, 67108832, 134217696, 268435424, 536870880
Offset: 0

Views

Author

Reinhard Zumkeller, Feb 28 2010

Keywords

Crossrefs

Sequences of the form m*(2^n - 1): A000225 (m=1), A000918 (m=2), A068156 (m=3), A028399 (m=4), A068293 (m=6), A159741 (m=8), A175164 (m=16), this sequence (m=32), A175166 (m=64).
Cf. A173787.

Programs

  • Magma
    I:=[0,32]; [n le 2 select I[n] else 3*Self(n-1) - 2*Self(n-2): n in [1..41]]; // G. C. Greubel, Jul 08 2021
    
  • Mathematica
    32(2^Range[0,30] -1) (* or *) LinearRecurrence[{3,-2},{0,32},30] (* Harvey P. Dale, Mar 23 2015 *)
  • Python
    def A175165(n): return (1<Chai Wah Wu, Jun 27 2023
  • Sage
    [32*(2^n -1) for n in (0..40)] # G. C. Greubel, Jul 08 2021
    

Formula

a(n) = 2^(n+5) - 32.
a(n) = A173787(n+5, 5).
a(n) = 3*a(n-1) - 2*a(n-2); a(0)=0, a(1)=32. - Vincenzo Librandi, Dec 28 2010
From G. C. Greubel, Jul 08 2021: (Start)
G.f.: 32*x/((1-x)*(1-2*x)).
E.g.f.: 32*(exp(2*x) - exp(x)). (End)

A371064 Array read by ascending antidiagonals where T(n,k) is the number of paths of length k from the origin to a facet of the cross polytope of size k in Z^n.

Original entry on oeis.org

2, 4, 2, 6, 12, 2, 8, 30, 28, 2, 10, 56, 126, 60, 2, 12, 90, 344, 462, 124, 2, 14, 132, 730, 1880, 1566, 252, 2, 16, 182, 1332, 5370, 9368, 5070, 508, 2, 18, 240, 2198, 12372, 36250, 43736, 15966, 1020, 2, 20, 306, 3376, 24710, 106452, 228090, 195224, 49422, 2044, 2
Offset: 1

Views

Author

Shel Kaphan, Mar 09 2024

Keywords

Comments

In the cross polytope of dimension n, each facet of dimension i-1 (i=1..n) has i^k paths of length k from the origin to its surface, and there are binomial(n,i)*2^i such facets. To avoid double counting, an alternating sum is used to add up the paths to all the facets.

Examples

			distance
 k      1   2    3      4       5        6         7          8
dims ----------------------------------------------------------
 n 1 |  2   2    2      2       2        2         2          2
   2 |  4  12   28     60     124      252       508       1020
   3 |  6  30  126    462    1566     5070     15966      49422
   4 |  8  56  344   1880    9368    43736    195224     844760
   5 | 10  90  730   5370   36250   228090   1359130    7771770
   6 | 12 132 1332  12372  106452   856212   6505812   47189652
   7 | 14 182 2198  24710  259574  2562182  23928758  213041990
   8 | 16 240 3376  44592  554416  6511920  72592816  772172592
		

Crossrefs

Columns: A002939 (k=2).
Rows: A028399 (n=2), A366058 (n=3).

Formula

T(n,k) = Sum_{i=1..n} (-1)^(n-i) * binomial(n,i) * 2^i * i^k.

A060158 Number of permutations of [n] with 4 sequences.

Original entry on oeis.org

0, 0, 0, 0, 0, 32, 300, 1852, 9576, 45096, 201060, 866324, 3650592, 15154240, 62260380, 253939116, 1030367448, 4165106264, 16790875860, 67553807428, 271383782544, 1089035545968, 4366631897100, 17497971562460, 70086163646280, 280627369334152, 1123357369925700
Offset: 0

Views

Author

Barbara Haas Margolius (margolius(AT)math.csuohio.edu), Mar 12 2001

Keywords

References

  • L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 261.

Crossrefs

Programs

  • Maple
    n4 := n->2*n-7+(6-n)*2^(n-1)-3^n+4^(n-1); seq(n4(i),i=5..27);
  • Mathematica
    Join[{0, 0}, LinearRecurrence[{13, -67, 175, -244, 172, -48}, {0, 0, 0, 32, 300, 1852}, 25]] (* Jean-François Alcover, Sep 02 2018 *)
  • PARI
    a(n) = { if (n<2, 0, 2*n - 7 + (6 - n)*2^(n - 1) - 3^n + 4^(n - 1)) } \\ Harry J. Smith, Jul 02 2009

Formula

a(n) = 2n - 7 + (6-n)*2^(n-1) - 3^n + 4^(n-1).
G.f.: 4*x^5*(8-29*x+24*x^2)/((1-4*x)*(1-3*x)*(1-2*x)^2*(1-x)^2).

Extensions

Edited by N. J. A. Sloane, Nov 11 2006
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