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 11 results. Next

A284663 Number of dominating sets in the Moebius ladder M_n.

Original entry on oeis.org

3, 15, 51, 179, 663, 2439, 8935, 32771, 120219, 440975, 1617531, 5933267, 21763823, 79831879, 292831311, 1074134531, 3940032883, 14452434639, 53012975555, 194456895859, 713287340551, 2616409296967, 9597250953527, 35203676264195, 129130605057163
Offset: 1

Views

Author

Eric W. Weisstein, Mar 31 2017

Keywords

Comments

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

Crossrefs

Cf. A182143, A284702, A218348 (ladder).

Programs

  • Mathematica
    LinearRecurrence[{3, 1, 5, 1, 1, -1, -1}, {3, 15, 51, 179, 663, 2439,
      8935}, 20] (* Eric W. Weisstein, May 17 2017 *)
    Rest[CoefficientList[Series[x*(1 - x)*(1 + x)*(3*x^4 + 2*x^3 + 6*x^2 + 6*x + 3)/((x^2 + 1)*(x^5 + x^4 - 2*x^3 - 2*x^2 - 3*x + 1)), {x,0,50}], x]] (* G. C. Greubel, May 17 2017 *)
    Table[RootSum[1 + # - 2 #^2 - 2 #^3 - 3 #^4 + #^5 &, #^n &] - 2 Cos[n Pi/2], {n, 20}] (* Eric W. Weisstein, Jun 14 2017 *)
  • PARI
    Vec((1-x)*(1+x)*(3*x^4+2*x^3+6*x^2+6*x+3)/((x^2+1)*(x^5+x^4-2*x^3-2*x^2-3*x+1))+O(x^50)) \\ 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) for n>7.
G.f.: x*(1-x)*(1+x)*(3*x^4+2*x^3+6*x^2+6*x+3)/((x^2+1)*(x^5+x^4-2*x^3 -2*x^2-3*x+1)). (End)

Extensions

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

A290336 Number of minimal dominating sets in the n-prism graph.

Original entry on oeis.org

11, 12, 37, 55, 149, 316, 596, 1219, 2444, 4971, 10103, 20465, 41746, 84924, 172501, 350668, 712597, 1448447, 2943959, 5983344, 12162310, 24720787, 50246512, 102129655, 207584129, 421928981, 857596064, 1743117100, 3543000201, 7201373724, 14637255611
Offset: 3

Views

Author

Eric W. Weisstein, Jul 27 2017

Keywords

Comments

The prism graphs are defined for n>=3. If the sequence is extended to n=1 using P_n X P_2 then a(1)=2 and a(2)=6 (as A290379). The empirical recurrence is the same as that for the Moebius ladder graph (see A290337). - Andrew Howroyd, Aug 01 2017

Crossrefs

Formula

Empirical: a(n) = a(n-1)+a(n-2)+2*a(n-3) -a(n-4)+2*a(n-5)-2*a(n-6) +6*a(n-7)+4*a(n-8)+4*a(n-9) -6*a(n-10)-3*a(n-12) +5*a(n-13)-a(n-14)-2*a(n-15) -5*a(n-16)-2*a(n-17)-2*a(n-18) for n > 20. - Andrew Howroyd, Aug 01 2017
Empirical g.f.: x^3*(11 + x + 14*x^2 - 16*x^3 + 44*x^4 + 28*x^5 + 56*x^6 - 52*x^7 - 6*x^8 - 70*x^9 + 52*x^10 - 28*x^11 - 23*x^12 - 97*x^13 - 56*x^14 - 62*x^15 - 12*x^16 - 8*x^17) / ((1 - x)*(1 + 2*x^4 + x^6)*(1 - x^2 - 3*x^3 - 4*x^4 - 4*x^5 - x^6 - 2*x^7 - 3*x^8 - 5*x^9 - 4*x^10 - 2*x^11)). - Colin Barker, Aug 02 2017

Extensions

Terms a(9) and beyond from Andrew Howroyd, Aug 01 2017

A286514 Array read by antidiagonals: T(m,n) = number of dominating sets in the stacked prism graph C_m X P_n.

Original entry on oeis.org

1, 3, 3, 5, 11, 7, 9, 41, 51, 11, 17, 149, 383, 183, 21, 31, 547, 2865, 2629, 663, 39, 57, 2007, 21449, 38437, 18635, 2435, 71, 105, 7361, 160579, 561743, 531669, 133709, 8935, 131, 193, 27001, 1202181, 8207075, 15179657, 7455797, 956009, 32775, 241
Offset: 1

Views

Author

Andrew Howroyd, May 10 2017

Keywords

Examples

			Table starts:
===========================================================
m\n|  1    2      3         4           5             6
---|-------------------------------------------------------
1  |  1    3      5         9          17            31 ...
2  |  3   11     41       149         547          2007 ...
3  |  7   51    383      2865       21449        160579 ...
4  | 11  183   2629     38437      561743       8207075 ...
5  | 21  663  18635    531669    15179657     433200191 ...
6  | 39 2435 133709   7455797   416118655   23213149395 ...
7  | 71 8935 956009 104209625 11369806353 1239821606103 ...
...
		

Crossrefs

Column 2 is A284702.
Row 3 is A285880.
Main diagonal is A286914.
Cf. A286513, A218354 (P_n X P_n).

A218348 Hilltop maps: number of n X 2 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..1 nX2 array.

Original entry on oeis.org

3, 11, 41, 149, 547, 2007, 7361, 27001, 99043, 363299, 1332617, 4888173, 17930307, 65770159, 241251521, 884934705, 3246028995, 11906758971, 43675182633, 160204937605, 587647732323, 2155550649479, 7906775346689, 29002842683433
Offset: 1

Views

Author

R. H. Hardin, Oct 26 2012

Keywords

Comments

Number of dominating sets in the ladder graph P_2 X P_n. - Andrew Howroyd, May 10 2017

Examples

			Some solutions for n=3
..1..0....1..1....0..1....1..0....1..1....1..1....0..1....0..0....1..0....0..1
..1..0....0..0....1..1....1..0....0..1....1..1....0..1....1..1....0..0....0..0
..0..1....1..1....0..1....1..0....1..0....1..0....1..0....0..0....0..1....1..0
		

Crossrefs

Column 2 of A218354.

Programs

  • Mathematica
    LinearRecurrence[{3, 2, 2, -1, -1}, {3, 11, 41, 149, 547}, 20]  (* Eric W. Weisstein, Jun 14 2017 *)
    CoefficientList[Series[(x (3 + 2 x + 2 x^2 - 2 x^3 - x^4))/(1 - 3 x - 2 x^2 - 2 x^3 + x^4 + x^5), {x, 0, 20}], x] (* Eric W. Weisstein, Jun 14 2017 *)
    Table[RootSum[1 + # - 2 #^2 - 2 #^3 - 3 #^4 + #^5 &, (-167 + 525 # - 73 #^2 + 819 #^3 - 218 #^4) #^n &]/2102, {n, 20}] (* Eric W. Weisstein, Jul 13 2017 *)
  • PARI
    Vec((3+2*x+2*x^2-2*x^3-x^4)/(1-3*x-2*x^2-2*x^3+x^4+x^5)+O(x^50)) \\ Andrew Howroyd, May 10 2017

Formula

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

A286914 Number of dominating sets in the stacked prism graph C_n X P_n.

Original entry on oeis.org

1, 11, 383, 38437, 15179657, 23213149395, 135207176568283, 3008600384479080345, 255856229024918222966821, 83138455533359719800266401039, 103225590675437292878209927396154515, 489730115155632619934278544711183719808829
Offset: 1

Views

Author

Andrew Howroyd, May 15 2017

Keywords

Crossrefs

Main diagonal of A286514.

A296102 Number of total dominating sets in the n-prism graph.

Original entry on oeis.org

3, 9, 39, 121, 443, 1521, 5071, 17161, 58035, 196249, 664183, 2247001, 7601259, 25715041, 86992799, 294294025, 995591267, 3368061225, 11394069191, 38545861561, 130399710235, 441139057489, 1492362749807, 5048627017225, 17079382868243, 57779138385081, 195465425009943
Offset: 1

Views

Author

Eric W. Weisstein, Apr 16 2018

Keywords

Comments

Sequence extrapolated to n=1 using recurrence. - Andrew Howroyd, Apr 16 2018

Crossrefs

Programs

  • Mathematica
    Table[RootSum[-1 - # - 3 #^2 + #^3 &, #^n &] + RootSum[1 + # - #^2 + #^3 &, #^n &] + RootSum[-1 + # + #^2 + #^3 &, #^n &], {n, 20}]
    LinearRecurrence[{3, 0, 4, -2, 10, 4, 0, -1, -1}, {3, 9, 39, 121, 443,
       1521, 5071, 17161, 58035}, 20]
    CoefficientList[Series[(3 + 12 x^2 - 8 x^3 + 50 x^4 + 24 x^5 - 8 x^7 - 9 x^8)/(1 - 3 x - 4 x^3 + 2 x^4 - 10 x^5 - 4 x^6 + x^8 + x^9), {x, 0, 20}], x]
  • PARI
    Vec((3 + 12*x^2 - 8*x^3 + 50*x^4 + 24*x^5 - 8*x^7 - 9*x^8)/((1 - x + x^2 + x^3)*(1 + x + x^2 - x^3)*(1 - 3*x - x^2 - x^3)) + O(x^30)) \\ Andrew Howroyd, Apr 16 2018

Formula

From Andrew Howroyd, Apr 16 2018: (Start)
G.f.: x*(3 + 12*x^2 - 8*x^3 + 50*x^4 + 24*x^5 - 8*x^7 - 9*x^8)/((1 - x + x^2 + x^3)*(1 + x + x^2 - x^3)*(1 - 3*x - x^2 - x^3)).
a(n) = 3*a(n-1) + 4*a(n-3) - 2*a(n-4) + 10*a(n-5) + 4*a(n-6) - a(n-8) - a(n-9) for n > 9. (End)

Extensions

a(1)-a(2) and terms a(10) and beyond from Andrew Howroyd, Apr 16 2018

A338153 a(n) is the number of acyclic orientations of the edges of the n-prism.

Original entry on oeis.org

204, 1862, 14700, 109334, 790524, 5633222, 39828300, 280376054, 1968934044, 13807724582, 96754776300, 677686169174, 4745413960764, 33224340503942, 232596153986700, 1628276158432694, 11398345428510684, 79790067272259302, 558537067986067500, 3909785864202510614
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 = 4, the 4-prism is the 3-dimensional cube, so a(4) = A334247(3) = 1862.
		

Crossrefs

Cf. A033815 (cross-polytope), A058809 (wheel), A334247 (cube), A338152 (n-demihypercube), A338154 (n-antiprism).

Programs

Formula

Conjectures from Colin Barker, Oct 13 2020: (Start)
G.f.: 2*x^3*(102 - 497*x + 742*x^2 - 392*x^3) / ((1 - x)*(1 - 2*x)*(1 - 4*x)*(1 - 7*x)).
a(n) = 14*a(n-1) - 63*a(n-2) + 106*a(n-3) - 56*a(n-4) for n>6.
(End)
a(n) = 5 + 7^n - 2^(n+1) - 2*4^n. - Peter Kagey, Nov 15 2020

A285880 Number of dominating sets in the stacked prism graph C_3 X P_n.

Original entry on oeis.org

7, 51, 383, 2865, 21449, 160579, 1202181, 9000177, 67380199, 504444655, 3776545835, 28273267057, 211668986689, 1584668649559, 11863687582089, 88817989227329, 664939560807015, 4978097605819019, 37268734233506311, 279013924866426465
Offset: 1

Views

Author

Andrew Howroyd, May 15 2017

Keywords

Crossrefs

Row 3 of A286514.

Formula

Empirical: a(n) = 7*a(n-1)+3*a(n-2)+5*a(n-3)-a(n-4)-3*a(n-5)-a(n-6)-a(n-7) for n>7.
Empirical G.f.: x*(7+2*x+5*x^2-4*x^3 -3*x^4-2*x^5-x^6)/(1-7*x-3*x^2-5*x^3 +x^4+3*x^5+x^6+x^7).

A286985 Number of connected dominating sets in the n-prism graph.

Original entry on oeis.org

7, 7, 39, 115, 343, 967, 2663, 7203, 19239, 50887, 133543, 348179, 902775, 2329607, 5986535, 15327555, 39115847, 99532423, 252601127, 639548595, 1615746455, 4073951559, 10253517671, 25763632995, 64635943783, 161928486727, 405134009511, 1012371656275
Offset: 1

Views

Author

Eric W. Weisstein, May 17 2017

Keywords

Comments

Sequence extrapolated to a(1) and a(2) using recurrence. - Andrew Howroyd, Sep 04 2017

Crossrefs

Programs

  • Mathematica
    Rest @ CoefficientList[Series[x (7 - 35 x + 74 x^2 - 70 x^3 + 19 x^4 - 3 x^5)/((1 - x)^2*(1 - 2 x - x^2)^2), {x, 0, 28}], x] (* Michael De Vlieger, Sep 04 2017 *)
    Table[LucasL[n, 2] + 2 n (3 Fibonacci[n - 2, 2] + Fibonacci[n - 1, 2] - 1) + 1, {n, 20}] (* Eric W. Weisstein, Sep 08 2017 *)
    LinearRecurrence[{6, -11, 4, 5, -2, -1}, {7, 7, 39, 115, 343, 967}, 20] (* Eric W. Weisstein, Sep 08 2017 *)
  • PARI
    Vec((7 - 35*x + 74*x^2 - 70*x^3 + 19*x^4 - 3*x^5)/((1 - x)^2*(1 - 2*x - x^2)^2) + O(x^30))

Formula

From Andrew Howroyd, Sep 04 2017: (Start)
a(n) = 6*a(n-1) - 11*a(n-2) + 4*a(n-3) + 5*a(n-4) - 2*a(n-5) - a(n-6) for n > 6.
G.f.: x*(7 - 35*x + 74*x^2 - 70*x^3 + 19*x^4 - 3*x^5)/((1 - x)^2*(1 - 2*x - x^2)^2).
(End)

Extensions

a(1)-a(2) and terms a(14) and beyond from Andrew Howroyd, Sep 04 2017

A290511 Number of irredundant sets in the n-prism graph.

Original entry on oeis.org

3, 9, 24, 77, 198, 522, 1550, 4477, 12732, 36214, 103579, 296294, 846303, 2417368, 6907329, 19737901, 56396602, 161138214, 460420182, 1315565162, 3758963099, 10740463083, 30688703123, 87686813998, 250547405698, 715888629491, 2045507376543, 5844625043236
Offset: 1

Views

Author

Eric W. Weisstein, Aug 04 2017

Keywords

Comments

The n-prism graph is well defined for n >= 3. Sequence extended to n=1 via the number of period n periodic solutions on a larger graph. - Andrew Howroyd, Aug 07 2017

Crossrefs

Formula

Empirical: a(n) = 3*a(n-1) - a(n-3) + 2*a(n-4) - 6*a(n-5) - 8*a(n-6) + 13*a(n-7) + 6*a(n-8) - 6*a(n-9) - 2*a(n-10) - 5*a(n-11) - 4*a(n-12) + 2*a(n-13) + 2*a(n-14) - a(n-15) + a(n-16) + 3*a(n-17) + 2*a(n-19) for n > 19. - Andrew Howroyd, Aug 07 2017

Extensions

a(1)-a(2) and terms a(10) and beyond from Andrew Howroyd, Aug 07 2017
Showing 1-10 of 11 results. Next