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.

Previous Showing 11-16 of 16 results.

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

A218349 Hilltop maps: number of nX3 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..1 nX3 array.

Original entry on oeis.org

5, 41, 291, 2069, 14811, 105913, 757305, 5415209, 38722037, 276885777, 1979899795, 14157473937, 101234450215, 723887182917, 5176228570197, 37013146305509, 264666248964889, 1892522801570497, 13532675845407459, 96766768350125913
Offset: 1

Views

Author

R. H. Hardin Oct 26 2012

Keywords

Comments

Column 3 of A218354

Examples

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

Formula

Empirical: a(n) = 6*a(n-1) +5*a(n-2) +22*a(n-3) +7*a(n-4) +8*a(n-5) -18*a(n-6) -20*a(n-7) -a(n-8) +4*a(n-9) +3*a(n-10) +a(n-12)

A218350 Hilltop maps: number of nX4 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..1 nX4 array.

Original entry on oeis.org

9, 149, 2069, 28661, 401253, 5609569, 78394141, 1095695529, 15314367301, 214044940145, 2991651891557, 41813576818545, 584417958076589, 8168264238929833, 114165795446827469, 1595666897305379897
Offset: 1

Views

Author

R. H. Hardin Oct 26 2012

Keywords

Comments

Column 4 of A218354

Examples

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

Formula

Empirical: a(n) = 10*a(n-1) +36*a(n-2) +242*a(n-3) +413*a(n-4) +482*a(n-5) -720*a(n-6) -2212*a(n-7) -683*a(n-8) +466*a(n-9) +121*a(n-10) -414*a(n-11) -119*a(n-12) -100*a(n-13) +241*a(n-14) +36*a(n-15) +164*a(n-16) -44*a(n-17) +35*a(n-18) -4*a(n-19) +2*a(n-20) +2*a(n-21) -a(n-22)

A218351 Hilltop maps: number of nX5 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..1 nX5 array.

Original entry on oeis.org

17, 547, 14811, 401253, 10982565, 300126903, 8199377227, 224032447213, 6121258910011, 167250519310183, 4569773233045519, 124859601874166153, 3411530022687206815, 93212992000176142919, 2546851962811003392065
Offset: 1

Views

Author

R. H. Hardin Oct 26 2012

Keywords

Comments

Column 5 of A218354

Examples

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

A218352 Hilltop maps: number of nX6 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..1 nX6 array.

Original entry on oeis.org

31, 2007, 105913, 5609569, 300126903, 16031828359, 856149291505, 45726317510017, 2442206384575879, 130435504723928475, 6966420606934069925, 372069142324752766777, 19871816932607721069123, 1061332595121563636599299
Offset: 1

Views

Author

R. H. Hardin Oct 26 2012

Keywords

Comments

Column 6 of A218354

Examples

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

A218353 Hilltop maps: number of nX7 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..1 nX7 array.

Original entry on oeis.org

57, 7361, 757305, 78394141, 8199377227, 856149291505, 89373230342147, 9330728065217697, 974144457139164177, 101701766819321353361, 10617786795585969799967, 1108509971334366966147185
Offset: 1

Views

Author

R. H. Hardin Oct 26 2012

Keywords

Comments

Column 7 of A218354

Examples

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