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 1-6 of 6 results.

A284702 Number of dominating sets in the n-prism graph.

Original entry on oeis.org

3, 11, 51, 183, 663, 2435, 8935, 32775, 120219, 440971, 1617531, 5933271, 21763823, 79831875, 292831311, 1074134535, 3940032883, 14452434635, 53012975555, 194456895863, 713287340551, 2616409296963, 9597250953527, 35203676264199, 129130605057163
Offset: 1

Views

Author

Eric W. Weisstein, Apr 01 2017

Keywords

Comments

Sequence extrapolated to n=1 using recurrence. - Andrew Howroyd, May 10 2017

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{3, 1, 5, 1, 1, -1, -1}, {3, 11, 51, 183, 663, 2435,
      8935}, 20] (* Eric W. Weisstein, May 17 2017 *)
    Rest[CoefficientList[Series[x (-7 x^6 - 6 x^5 + 5 x^4 + 4 x^3 + 15 x^2 + 2 x + 3)/((x^2 + 1) (x^5 + x^4 - 2 x^3 - 2 x^2 - 3 x + 1)), {x, 0, 20}], x]] (* G. C. Greubel, May 17 2017 *)
    Table[2 Cos[n Pi/2] + RootSum[1 + #1 - 2 #1^2 - 2 #1^3 - 3 #1^4 + #1^5 &, #^n &], {n, 20}] (* Eric W. Weisstein, May 26 2017 *)
  • PARI
    Vec((-7*x^6-6*x^5+5*x^4+4*x^3+15*x^2+2*x+3)/((x^2+1)*(x^5+x^4-2*x^3-2*x^2-3*x+1))+O(x^15)) \\ Andrew Howroyd, May 10 2017

Formula

From Andrew Howroyd, May 10 2017: (Start)
a(n) = 3*a(n-1) + a(n-2) + 5*a(n-3) + a(n-4) + a(n-5) - a(n-6) - a(n-7).
G.f.: x*(-7*x^6 - 6*x^5 + 5*x^4 + 4*x^3 + 15*x^2 + 2*x + 3)/((x^2 + 1)*(x^5 + x^4 - 2*x^3 - 2*x^2 - 3*x + 1)). (End)

Extensions

a(1)-a(2) and a(16)-a(25) from Andrew Howroyd, May 10 2017

A284700 Number of edge covers in the n-antiprism graph.

Original entry on oeis.org

4, 13, 205, 2902, 41413, 590758, 8427370, 120219259, 1714968133, 24464596729, 348995693650, 4978540849669, 71020558255594, 1013132129923498, 14452670295681235, 206172198577335937, 2941115696724530533, 41956003773586931038, 598516493115066264085
Offset: 0

Views

Author

Eric W. Weisstein, Apr 01 2017

Keywords

Comments

Sequence extrapolated to n=0 using recurrence. - Andrew Howroyd, May 15 2017

Crossrefs

Programs

  • Mathematica
    Table[RootSum[4 - # - 18 #^2 - 13 #^3 + #^4 &, #^n &], {n, 0, 20}] (* Eric W. Weisstein, May 17 2017 *)
    LinearRecurrence[{13, 18, 1, -4}, {13, 205, 2902, 41413}, {0, 20}] (* Eric W. Weisstein, May 17 2017 *)
    CoefficientList[Series[(-x^3-36*x^2-39*x+4)/(4*x^4-x^3-18*x^2-13*x+1), {x, 0, 50}], x]
  • PARI
    Vec((-x^3-36*x^2-39*x+4)/(4*x^4-x^3-18*x^2-13*x+1)+O(x^20)) \\ Andrew Howroyd, May 15 2017

Formula

From Andrew Howroyd, May 15 2017 (Start)
a(n) = 13*a(n-1)+18*a(n-2)+a(n-3)-4*a(n-4) for n>=4.
G.f.: (-x^3-36*x^2-39*x+4)/(4*x^4-x^3-18*x^2-13*x+1).
(End)

Extensions

a(0)-a(2) and a(9)-a(18) from Andrew Howroyd, May 15 2017

A290377 Number of minimal dominating sets in the n-antiprism graph.

Original entry on oeis.org

4, 15, 12, 25, 55, 112, 188, 438, 789, 1573, 3135, 5980, 11848, 23035, 45020, 87873, 171910, 335464, 655397, 1281190, 2501173, 4888098, 9548543, 18653025, 36441500, 71190933, 139076320, 271694910, 530784135, 1036914040, 2025703900, 3957367099, 7731003525
Offset: 2

Views

Author

Eric W. Weisstein, Jul 28 2017

Keywords

Crossrefs

Formula

Empirical: a(n) = 2*a(n-2)+5*a(n-3)+a(n-4) -5*a(n-5)-8*a(n-6)+a(n-7) +6*a(n-8)+10*a(n-9)-2*a(n-10) -2*a(n-11)-5*a(n-12)+a(n-15) for n>16. - Andrew Howroyd, Aug 01 2017
Empirical g.f.: x^2*(4 + 15*x + 4*x^2 - 25*x^3 - 48*x^4 + 7*x^5 + 48*x^6 + 90*x^7 - 20*x^8 - 22*x^9 - 60*x^10 + 15*x^13) / (1 - 2*x^2 - 5*x^3 - x^4 + 5*x^5 + 8*x^6 - x^7 - 6*x^8 - 10*x^9 + 2*x^10 + 2*x^11 + 5*x^12 - x^15). - Colin Barker, Aug 01 2017

Extensions

a(2) and terms a(8) and beyond from Andrew Howroyd, Aug 01 2017

A338154 a(n) is the number of acyclic orientations of the edges of the n-antiprism.

Original entry on oeis.org

426, 4968, 50640, 486930, 4547088, 41796168, 380789562, 3451622904, 31194607488, 281440825122, 2536622917920, 22848990484344, 205743704494026, 1852238413383048, 16673036119790640, 150072652217086770, 1350735146332489008, 12157047307392618408
Offset: 3

Views

Author

Peter Kagey, Oct 13 2020

Keywords

Comments

Conjectured linear recurrence and g.f. confirmed by Kagey's formula. - Ray Chandler, Mar 10 2024

Examples

			For n = 3, the 3-antiprism is the octahedron (3-dimensional cross-polytope), so a(3) = A033815(3) = 426.
		

Crossrefs

Cf. A033815 (cross-polytope), A058809 (wheel), A334247 (hypercube), A338152 (demihypercube), A338153 (prism).

Programs

  • Mathematica
    A338154[n_] := Round[-2^(1-n)*((7 - Sqrt[13])^n + (7 + Sqrt[13])^n) + 9^n + 5] (* Peter Kagey, Nov 15 2020 *)

Formula

Conjectures from Colin Barker, Oct 13 2020: (Start)
G.f.: 6*x^3*(71 - 379*x + 612*x^2 - 324*x^3) / ((1 - x)*(1 - 9*x)*(1 - 7*x + 9*x^2)).
a(n) = 17*a(n-1) - 88*a(n-2) + 153*a(n-3) - 81*a(n-4) for n>6.
(End)
a(n) = -2^(1-n)*((7-sqrt(13))^n + (7+sqrt(13))^n) + 9^n + 5. - Peter Kagey, Nov 15 2020

A290510 Number of irredundant sets in the n-antiprism graph.

Original entry on oeis.org

1, 5, 22, 37, 76, 194, 491, 1125, 2731, 6640, 15962, 38386, 92639, 223403, 538102, 1297061, 3126726, 7535759, 18162481, 43777272, 105514634, 254314406, 612962766, 1477397778, 3560896401, 8582652759, 20686361179, 49859334611, 120173522734, 289648431514
Offset: 1

Views

Author

Eric W. Weisstein, Aug 04 2017

Keywords

Comments

The n-antiprism graphs are well defined for n>=3. Sequence extendend to n=1 using recurrence. - Andrew Howroyd, Aug 05 2017

Crossrefs

Formula

Empirical: a(n) = a(n-1)+2*a(n-2)+5*a(n-3) -6*a(n-5)-10*a(n-6) +6*a(n-8)+10*a(n-9)-a(n-10) -2*a(n-11)-5*a(n-12)+a(n-15) for n>15. - Andrew Howroyd, Aug 05 2017
Empirical g.f.: x*(1 + 4*x + 15*x^2 - 30*x^4 - 60*x^5 + 48*x^7 + 90*x^8 - 10*x^9 - 22*x^10 - 60*x^11 + 15*x^14) / ((1 - x)*(1 + x + x^2)*(1 - x - 2*x^2 - 4*x^3 - x^4 + 4*x^5 + 6*x^6 - x^7 - 2*x^8 - 4*x^9 + x^12)). - Colin Barker, Aug 05 2017

Extensions

a(1)-a(2) and terms a(11) and beyond from Andrew Howroyd, Aug 05 2017

A304568 Number of minimum dominating sets in the n-antiprism graph.

Original entry on oeis.org

2, 4, 15, 12, 5, 40, 14, 140, 45, 5, 154, 24, 546, 98, 5, 384, 34, 1485, 171, 5, 770, 44, 3289, 264, 5, 1352, 54, 6370, 377, 5, 2170, 64, 11220, 510, 5, 3264, 74, 18411, 663, 5, 4674, 84, 28595, 836, 5, 6440, 94, 42504, 1029, 5, 8602, 104, 60950, 1242, 5
Offset: 1

Views

Author

Eric W. Weisstein, May 14 2018

Keywords

Comments

Sequence extrapolated to n=1 using formula. - Andrew Howroyd, May 20 2018

Crossrefs

Programs

  • Mathematica
    Table[Piecewise[{{5, Mod[n, 5] == 0}, {2 n (4 + n) (13 + 2 n)/75, Mod[n, 5] == 1}, {2 n, Mod[n, 5] == 2}, {n (7 + n) (9 + 2 n) (19 + 2 n)/750, Mod[n, 5] == 3}, {n (7 + 2 n)/5, Mod[n, 5] == 4}}], {n, 30}]
    LinearRecurrence[{0, 0, 0, 0, 5, 0, 0, 0, 0, -10, 0, 0, 0, 0, 10, 0, 0, 0, 0, -5, 0, 0, 0, 0, 1}, {2, 4, 15, 12, 5, 40, 14, 140, 45, 5, 154, 24, 546, 98, 5, 384, 34, 1485, 171, 5, 770, 44, 3289, 264, 5}, 30]
    CoefficientList[Series[(5 x^4)/(1 - x^5) + (2 x (2 + 3 x^5))/(-1 + x^5)^2 + (x^3 (-12 - 9 x^5 + x^10))/(-1 + x^5)^3 + (2 (1 + 16 x^5 + 3 x^10))/(-1 + x^5)^4 + (x^2 (-15 - 65 x^5 + 4 x^10 - 5 x^15 + x^20))/(-1 + x^5)^5, {x, 0, 30}], x]
  • PARI
    a(n)={[k->5, k->2*(5*k+1)*(k+1)*(2*k+3)/3, k->2*(5*k+2), k->(5*k+3)*(2*k+5)*(2*k+4)*(2*k+3)/12, k->(5*k+4)*(2*k+3)][n%5+1](n\5)} \\ Andrew Howroyd, May 20 2018
    
  • PARI
    Vec(x*(2 + 4*x + 15*x^2 + 12*x^3 + 5*x^4 + 30*x^5 - 6*x^6 + 65*x^7 - 15*x^8 - 20*x^9 - 26*x^10 - 6*x^11 - 4*x^12 - 7*x^13 + 30*x^14 - 6*x^15 + 14*x^16 + 5*x^17 + 11*x^18 - 20*x^19 - 6*x^21 - x^22 - x^23 + 5*x^24) / ((1 - x)^5*(1 + x + x^2 + x^3 + x^4)^5) + O(x^40)) \\ Colin Barker, May 22 2018

Formula

From Andrew Howroyd, May 20 2018: (Start)
a(n) = 5*a(n-5) - 10*a(n-10) + 10*a(n-15) - 5*a(n-20) + a(n-25) for n > 25.
a(5*k) = 5, a(5*k+1) = 2*(5*k+1)*(k+1)*(2*k+3)/3, a(5*k+2) = 2*(5*k+2), a(5*k+3) = (5*k+3)*(2*k+5)*(2*k+4)*(2*k+3)/12, a(5*k+4)=(5*k+4)*(2*k+3). (End)
G.f.: x*(2 + 4*x + 15*x^2 + 12*x^3 + 5*x^4 + 30*x^5 - 6*x^6 + 65*x^7 - 15*x^8 - 20*x^9 - 26*x^10 - 6*x^11 - 4*x^12 - 7*x^13 + 30*x^14 - 6*x^15 + 14*x^16 + 5*x^17 + 11*x^18 - 20*x^19 - 6*x^21 - x^22 - x^23 + 5*x^24) / ((1 - x)^5*(1 + x + x^2 + x^3 + x^4)^5). - Colin Barker, May 22 2018

Extensions

a(1)-a(2) and terms a(21) and beyond from Andrew Howroyd, May 20 2018
Showing 1-6 of 6 results.