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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A342088 Triangle read by rows: T(n,k) is the number of n-colorings of the vertices of the k-dimensional cross polytope such that no two adjacent vertices have the same color. 0 <= k <= n.

Original entry on oeis.org

1, 1, 1, 1, 4, 2, 1, 9, 18, 6, 1, 16, 84, 96, 24, 1, 25, 260, 780, 600, 120, 1, 36, 630, 4080, 7560, 4320, 720, 1, 49, 1302, 15330, 61320, 78120, 35280, 5040, 1, 64, 2408, 45696, 351120, 913920, 866880, 322560, 40320
Offset: 0

Views

Author

Peter Kagey, Feb 27 2021

Keywords

Examples

			Triangle begins:
  n\k| 0   1     2      3       4       5       6       7      8
  ---+----------------------------------------------------------
   0 | 1
   1 | 1,  1
   2 | 1,  4,    2
   3 | 1,  9,   18,     6
   4 | 1, 16,   84,    96,     24
   5 | 1, 25,  260,   780,    600,    120
   6 | 1, 36,  630,  4080,   7560,   4320,    720
   7 | 1, 49, 1302, 15330,  61320,  78120,  35280,   5040
   8 | 1, 64, 2408, 45696, 351120, 913920, 866880, 322560, 40320
		

Crossrefs

Cf. A000012 (k=0), A000290 (k=1), A091940 (k=2), A115400 (k=3), A334281 (k=4), A342073 (k=5), A342074 (k=6), A342075 (k=7).
Cf. A334279.

Programs

  • Mathematica
    T[n_, k_] := Sum[n! k!/((n - k - j)! (k - j)! j!), {j, 0, k}]

Formula

T(n,n) = n!.
T(n,k) = Sum_{i=0..2*k} A334279(k,i)*n^i.
T(n,k) = n*T(n-1,k-1) + n*(n-1)*T(n-2,k-1).
T(n,k) = Sum_{j=0..k} n!k!/((n-k-j)!(k-j)!j!).

A123659 a(n) = 1 + n^4 + n^6 + n^9 + n^10 + n^14.

Original entry on oeis.org

6, 18001, 4862512, 269750529, 6115250626, 78434755921, 678546021756, 4399254736897, 22880667197854, 100011001010001, 379778130741736, 1283985544700161, 3937524853545882, 11112316748827729, 29193541130581876
Offset: 1

Views

Author

Jonathan Vos Post, Oct 05 2006

Keywords

Crossrefs

Programs

  • Magma
    [1 + n^4 + n^6 + n^9 + n^10 + n^14: n in [1..25]]; // G. C. Greubel, Oct 17 2017
  • Mathematica
    Table[1 + n^4 + n^6 + n^9 + n^10 + n^14, {n, 1, 50}] (* G. C. Greubel, Oct 17 2017 *)
  • PARI
    for(n=1,25, print1(1 + n^4 + n^6 + n^9 + n^10 + n^14, ", ")) \\ G. C. Greubel, Oct 17 2017
    

Formula

a(n) = 1 + n^4 + n^6 + n^9 + n^10 + n^14.

A131472 a(n) = n^6 + n.

Original entry on oeis.org

0, 2, 66, 732, 4100, 15630, 46662, 117656, 262152, 531450, 1000010, 1771572, 2985996, 4826822, 7529550, 11390640, 16777232, 24137586, 34012242, 47045900, 64000020, 85766142, 113379926, 148035912, 191103000, 244140650, 308915802
Offset: 0

Views

Author

Mohammad K. Azarian, Jul 27 2007

Keywords

Crossrefs

Programs

  • Magma
    [n^6+n: n in [0..30]]; // _Vincenzo Librandi+, Oct 01 2011
  • Mathematica
    Table[n^6+n,{n,0,60}] (* Vladimir Joseph Stephan Orlovsky, May 12 2011 *)
    LinearRecurrence[{7,-21,35,-35,21,-7,1},{0,2,66,732,4100,15630,46662},60] (* Harvey P. Dale, May 03 2012 *)

Formula

G.f.: 2*x*(1 + 26*x + 156*x^2 + 146*x^3 + 31*x^4)/(1 - x)^7. - R. J. Mathar, Nov 14 2007
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7); a(0)=0, a(1)=2, a(2)=66, a(3)=732, a(4)=4100, a(5)=15630, a(6)=46662. - Harvey P. Dale, May 03 2012
E.g.f.: exp(x)*x*(2 + 31*x + 90*x^2 + 65*x^3 + 15*x^4 + x^5). - Stefano Spezia, Oct 08 2022

A342073 Number of n-colorings of the vertices of the 5-dimensional cross polytope such that no two adjacent vertices have the same color.

Original entry on oeis.org

0, 0, 0, 0, 0, 120, 4320, 78120, 913920, 7575120, 46751040, 224587440, 881591040, 2946869640, 8659691040, 22915652760, 55611279360, 125508233760, 266320172160, 535945217760, 1030028705280, 1901347885080, 3386866301280, 5844714201480, 9803816225280
Offset: 0

Views

Author

Peter Kagey, Feb 27 2021

Keywords

Crossrefs

Analogous for k-dimensional cross polytope: A091940 (k=2), A115400 (k=3), A334281 (k=4), A342074 (k=6), A342075 (k=7)

Programs

  • Mathematica
    p = ChromaticPolynomial[CompleteGraph[Table[2, 5]], x];
    Table[p /. x -> n, {n, 0, 50}]

Formula

a(n) = -205056*n + 593016*n^2 - 698250*n^3 + 448015*n^4 - 175004*n^5 + 43608*n^6 - 6990*n^7 + 700*n^8 - 40*n^9 + n^10.
a(n) = (n - 4)*(n - 3)*(n - 2)*(n - 1)*n*(-8544 + 6909*n - 2240*n^2 + 365*n^3 - 30*n^4 + n^5).
a(n) = Sum_{i=1..10} A334279(5,i)*n^i.
From Chai Wah Wu, Jan 19 2024: (Start)
a(n) = 11*a(n-1) - 55*a(n-2) + 165*a(n-3) - 330*a(n-4) + 462*a(n-5) - 462*a(n-6) + 330*a(n-7) - 165*a(n-8) + 55*a(n-9) - 11*a(n-10) + a(n-11) for n > 10.
G.f.: x^5*(-2170680*x^5 - 1145400*x^4 - 272400*x^3 - 37200*x^2 - 3000*x - 120)/(x - 1)^11. (End)

A342074 Number of n-colorings of the vertices of the 6-dimensional cross polytope such that no two adjacent vertices have the same color.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 720, 35280, 866880, 13849920, 158004000, 1347524640, 8866186560, 46496324160, 201705744240, 748737990000, 2444976293760, 7178449299840, 19276199691840, 47983899216960, 111920569776000, 246727594270080, 517702915311120, 1039979954779920
Offset: 0

Views

Author

Peter Kagey, Feb 27 2021

Keywords

Crossrefs

Analogous for k-dimensional cross polytope: A091940 (k=2), A115400 (k=3), A334281 (k=4), A342073 (k=5), A342075 (k=7).

Programs

  • Mathematica
    p = ChromaticPolynomial[CompleteGraph[Table[2, 6]], x];
    Table[p /. x -> n, {n, 0, 50}]

Formula

a(n) = -22852200*n + 70164670*n^2 - 89812001*n^3 + 64407806*n^4 - 29113410*n^5 + 8790285*n^6 - 1822164*n^7 + 260868*n^8 - 25405*n^9 + 1610*n^10 - 60*n^11 + n^12.
a(n) = (n - 5)*(n - 4)*(n - 3)*(n - 2)*(n - 1)*n*(190435 - 149879*n + 49144*n^2 - 8605*n^3 + 850*n^4 - 45*n^5 + n^6).
a(n) = Sum_{i=1..12} A334279(6,i)*n^i.
From Chai Wah Wu, Jan 19 2024: (Start)
a(n) = 13*a(n-1) - 78*a(n-2) + 286*a(n-3) - 715*a(n-4) + 1287*a(n-5) - 1716*a(n-6) + 1716*a(n-7) - 1287*a(n-8) + 715*a(n-9) - 286*a(n-10) + 78*a(n-11) - 13*a(n-12) + a(n-13) for n > 12.
G.f.: x^6*(-287250480*x^6 - 150137280*x^5 - 35996400*x^4 - 5126400*x^3 - 464400*x^2 - 25920*x - 720)/(x - 1)^13. (End)

A342075 Number of n-colorings of the vertices of the 7-dimensional cross polytope such that no two adjacent vertices have the same color.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 5040, 322560, 10342080, 216518400, 3261535200, 37026823680, 325474269120, 2264594492160, 12789814237200, 60389186457600, 245221330273920, 877374833287680, 2821277454690240, 8284633867238400, 22503569636419200, 57135310310453760
Offset: 0

Views

Author

Peter Kagey, Feb 27 2021

Keywords

Crossrefs

Analogous for k-dimensional cross polytope: A091940 (k=2), A115400 (k=3), A334281 (k=4), A342073 (k=5), A342074 (k=6).

Programs

  • Mathematica
    p = ChromaticPolynomial[CompleteGraph[Table[2, 7]], x];
    Table[p /. x -> n, {n, 0, 50}]

Formula

a(n) = -3597143040*n + 11590795728*n^2 - 15837356724*n^3 + 12355698460*n^4 - 6212542175*n^5 + 2144307578*n^6 - 526197678*n^7 + 93450369*n^8 - 12064836*n^9 + 1122618*n^10 - 73423*n^11 + 3206*n^12 - 84*n^13 + n^14.
a(n) = (n - 6)*(n - 5)*(n - 4)*(n - 3)*(n - 2)*(n - 1)*n*(n^7 - 63 n^6 + 1708 n^5 - 25795 n^4 + 234094 n^3 - 1275281 n^2 + 3858049 n - 4996032).
a(n) = Sum_{i=1..14} A334279(7,i)*n^i.
From Chai Wah Wu, Jan 19 2024: (Start)
a(n) = 15*a(n-1) - 105*a(n-2) + 455*a(n-3) - 1365*a(n-4) + 3003*a(n-5) - 5005*a(n-6) + 6435*a(n-7) - 6435*a(n-8) + 5005*a(n-9) - 3003*a(n-10) + 1365*a(n-11) - 455*a(n-12) + 105*a(n-13) - 15*a(n-14) + a(n-15) for n > 14.
G.f.: x^7*(-52370755920*x^7 - 27190754640*x^6 - 6557740560*x^5 - 959792400*x^4 - 92962800*x^3 - 6032880*x^2 - 246960*x - 5040)/(x - 1)^15. (End)

A380589 Number of n-colorings of the Hypercube Graph Q5.

Original entry on oeis.org

0, 0, 2, 1185282, 130253748108, 2157531034816940, 7905235551766437150, 7365707045872206479742, 2337101560809838105414712, 327425229254999498091796728, 24489214732779742874109277530, 1119349138930999380736025706650, 34471067091433681765512048700932
Offset: 0

Views

Author

Alois P. Heinz, Jan 27 2025

Keywords

Comments

The Hypercube Graph Q5 has 32 vertices and 80 edges.
All terms are even.

Crossrefs

Programs

  • Maple
    a:= n-> (((((((((((((((((((((((((((((((n-80)*n+3160)*n-82080)*n+1575420)*n
        -23805776)*n+294640000)*n-3068289720)*n+27406254870)*n-212981036784)*n
        +1455643449120)*n-8822129447280)*n+47712047044920)*n-231347639674200)*n
        +1009138022379076)*n-3968583456247214)*n+14086095737441185)*n-45124968898112160)*n
        +130327084318442384)*n-338572422663483544)*n+788328935798745052)*n
        -1636781898149840504)*n+3009654466362869780)*n-4856773984500880124)*n
        +6797172300402030636)*n-8122089299204814072)*n+8114599308192145448)*n
        -6584797184952049568)*n+4160914137061367054)*n-1915734714629493936)*n
        +569711421560808713)*n-81768640551939777)*n:
    seq(a(n), n=0..12);

Formula

a(n) = n^32 - 80*n^31 + 3160*n^30 - ... (see Maple program).

A123657 a(n) = 1 + n^4 + n^6 + n^9.

Original entry on oeis.org

4, 593, 20494, 266497, 1969376, 10125649, 40473658, 134483969, 387958492, 1001010001, 2359733894, 5162787073, 10609354744, 20668614737, 38454800626, 68736319489, 118612097588, 198393407569, 322734873982, 512064160001
Offset: 1

Views

Author

Jonathan Vos Post, Oct 04 2006

Keywords

Crossrefs

Programs

Formula

a(n) = 1 + n^4 + n^6 + n^9 = 1001010001 (base n).
G.f.: -x*(x^9 -8*x^8 -406*x^7 -14592*x^6 -88496*x^5 -156316*x^4 -87762*x^3 -14744*x^2 -553*x -4)/(x-1)^10. - Colin Barker, May 27 2012

A123665 a(n) = Sum_{k=1..21} n^A001358(k).

Original entry on oeis.org

22, 471260364628084305, 6457022669043550542502557676, 105149403852520725445003265581519105, 41911381174488637014293971538580334000626
Offset: 1

Views

Author

Jonathan Vos Post, Oct 04 2006

Keywords

Crossrefs

Programs

  • Magma
    [1 + n^4 + n^6 + n^9 + n^10 + n^14 + n^15 + n^21 + n^22 + n^25 +
    n^26 + n^33 + n^34 + n^35 + n^38 + n^39 + n^46 + n^49 + n^51 + n^55 + n^57 + n^58: n in [1..50]]; // G. C. Greubel, Oct 26 2017
  • Mathematica
    Table[1 + n^4 + n^6 + n^9 + n^10 + n^14 + n^15 + n^21 + n^22 + n^25 +
      n^26 + n^33 + n^34 + n^35 + n^38 + n^39 + n^46 + n^49 + n^51 +
      n^55 + n^57 + n^58, {n, 1, 50}] (* G. C. Greubel, Oct 26 2017 *)
  • PARI
    for(n=1,50, print1(1 + n^4 + n^6 + n^9 + n^10 + n^14 + n^15 + n^21 + n^22 + n^25 + n^26 + n^33 + n^34 + n^35 + n^38 + n^39 + n^46 + n^49 + n^51 + n^55 + n^57 + n^58, ", ")) \\ G. C. Greubel, Oct 26 2017
    

Formula

a(n) = 1 +n^4 +n^6 +n^9 +n^10 +n^14 +n^15 +n^21 +n^22 +n^25 +n^26 + n^33 +n^34 +n^35 +n^38 +n^39 +n^46 +n^49 +n^51 +n^55 +n^57 +n^58.

Extensions

Better name from Joerg Arndt, May 23 2021

A190578 a(n) = n^7 + n.

Original entry on oeis.org

0, 2, 130, 2190, 16388, 78130, 279942, 823550, 2097160, 4782978, 10000010, 19487182, 35831820, 62748530, 105413518, 170859390, 268435472, 410338690, 612220050, 893871758, 1280000020, 1801088562, 2494357910, 3404825470, 4586471448
Offset: 0

Views

Author

Keywords

Comments

a(n) = n^7 + n, A005843 for k=1, A002378 for k=2, A034262 for k=3, A091940 for k=4, A131471 for k=5, A131472 for k=6.

Crossrefs

Programs

  • Magma
    [n^7+n: n in [0..30]]; // Vincenzo Librandi, Sep 30 2011
  • Mathematica
    k=7; Table[n^k+n,{n,0,50}]

Extensions

Offset changed from 1 to 0 by Vincenzo Librandi, Sep 30 2011
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