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

A207724 Number of n X 3 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

6, 36, 78, 189, 490, 1113, 2449, 5474, 12036, 26100, 56595, 122472, 264061, 568695, 1224190, 2633000, 5660226, 12165489, 26141850, 56165805, 120662377, 259206930, 556801480, 1196027864, 2569059663, 5518244160, 11852866905, 25459111647
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2012

Keywords

Comments

Column 3 of A207729.

Examples

			Some solutions for n=4:
  1 1 0   1 1 1   1 0 0   1 0 0   0 1 1   0 1 1   0 0 1
  1 0 1   1 1 1   1 0 0   1 1 1   0 1 1   1 1 1   1 1 1
  1 0 0   1 1 0   1 0 0   1 0 0   1 1 1   0 1 1   0 0 1
  1 1 0   1 0 0   1 1 1   1 0 0   0 0 1   0 1 1   0 0 1
		

Crossrefs

Cf. A207729.

Programs

  • Maple
    Configs:= select(A -> A[1..3] <> [0,0,0] and A[4..6] <> [0,0,0] and A[1..3] <> [0,1,0] and A[4..6] <> [0,1,0],
    [seq(convert(x,base,2)[1..6],x=2^6..2^7-1)]):
    compat:= proc(i,j) local k,col;
       if Configs[i][4..6] <> Configs[j][1..3] then return 0 fi;
       for k from 1 to 3 do
          col:= [Configs[i][k],Configs[i][k+3],Configs[j][k+3]];
          if col = [0,1,1] or col = [1,0,1] then return 0 fi;
       od;
       1
    end proc:
    T:= Matrix(36,36,compat):
    u:= Vector[row](36, 1):
    v:= Vector(36,1):
    6,seq(u . T^(n-2) . v,n=2..50); # Robert Israel, Mar 05 2018
  • Mathematica
    LinearRecurrence[{3, -2, 3, -6, 0, 0, 3, 1, 0, -1}, {6, 36, 78, 189, 490, 1113, 2449, 5474, 12036, 26100}, 30] (* Jean-François Alcover, May 15 2023, after Robert Israel's confirmed formula *)

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 3*a(n-3) - 6*a(n-4) + 3*a(n-7) + a(n-8) - a(n-10).
Formula confirmed by Robert Israel, Mar 05 2018 (see link).
G.f.: x*(6 + 18*x - 18*x^2 + 9*x^3 + 7*x^4 + 3*x^5 - 9*x^6 - x^7 - x^8 + x^9) / ((1 - x)*(1 + x^2 - x^3)*(1 - x - x^3)*(1 - x - 2*x^2 - x^3)). - Colin Barker, Mar 05 2018

A207730 Number of 3 X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

6, 36, 78, 169, 611, 2209, 6016, 16384, 51840, 164025, 478305, 1394761, 4249238, 12945604, 38516590, 114597025, 345332595, 1040643081, 3114412896, 9320743936, 27998628896, 84105220081, 252138754753, 755885919889, 2268515874246
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2012

Keywords

Comments

Row 3 of A207729.

Examples

			Some solutions for n=4:
..1..0..1..1....0..1..1..1....0..0..1..1....1..1..1..1....0..1..1..1
..0..0..1..1....1..1..1..1....1..1..1..1....0..0..1..1....0..1..1..1
..0..1..1..1....0..0..1..1....0..0..1..1....0..0..1..1....0..0..1..1
		

Crossrefs

Cf. A207729.

Formula

Empirical: a(n) = 2*a(n-1) + 5*a(n-3) + 22*a(n-4) - 24*a(n-5) - 15*a(n-6) - 36*a(n-8) + 27*a(n-9).
Empirical g.f.: x*(6 + 24*x + 6*x^2 - 17*x^3 - 39*x^4 - 51*x^5 - 9*x^6 - 9*x^7 + 27*x^8) / ((1 - 3*x)*(1 + x - x^2)*(1 + x^2)*(1 + 3*x^2 - 9*x^4)). - Colin Barker, Mar 05 2018

A207723 Number of n X n 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

2, 16, 78, 441, 8575, 277729, 4799749, 93547584, 8978585264, 1701743731081, 92421758243781, 5198831216732241, 3314060538084914409, 4426079717506620317769, 675694617961142291654422
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2012

Keywords

Comments

Diagonal of A207729.

Examples

			Some solutions for n=4
..0..1..1..0....0..0..1..1....1..0..1..1....1..1..1..1....1..1..0..0
..1..1..1..0....0..1..1..1....1..1..0..1....1..1..1..1....1..1..0..1
..0..1..1..1....1..0..1..1....1..0..0..1....1..1..1..1....1..1..0..0
..0..1..1..0....0..0..1..1....0..0..1..1....0..1..1..1....0..1..1..0
		

Crossrefs

Cf. A207729.

A207725 Number of n X 4 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

9, 81, 169, 441, 1225, 2809, 6241, 14161, 31329, 68121, 148225, 321489, 693889, 1495729, 3222025, 6932689, 14907321, 32046921, 68873401, 147987225, 317944561, 683038225, 1467273025, 3151811881, 6770162961, 14542189281, 31235967169
Offset: 1

Views

Author

R. H. Hardin, Feb 19 2012

Keywords

Comments

Column 4 of A207729.

Examples

			Some solutions for n=4:
..1..1..1..0....1..1..0..0....0..0..1..1....1..0..0..1....1..1..0..0
..1..1..0..1....1..1..0..1....1..0..1..1....1..0..0..1....1..1..0..1
..1..1..0..0....1..1..1..0....0..1..1..1....1..1..0..1....1..1..0..0
..0..1..1..0....1..1..0..0....0..0..1..1....1..0..0..1....0..1..1..0
		

Crossrefs

Cf. A207729.

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 3*a(n-3) - 6*a(n-4) + 3*a(n-7) + a(n-8) - a(n-10).
Empirical g.f.: x*(9 + 54*x - 56*x^2 + 69*x^3 + 51*x^4 - 5*x^5 - 45*x^6 - x^8 - x^9) / ((1 - x)*(1 + x^2 - x^3)*(1 - x - x^3)*(1 - x - 2*x^2 - x^3)). - Colin Barker, Jun 25 2018

A207726 Number of nX5 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

15, 225, 611, 2163, 8575, 27931, 88243, 288813, 926949, 2927115, 9278885, 29390445, 92717065, 292337359, 921806095, 2904391209, 9147369231, 28808166663, 90713456051, 285607327515, 899181685831, 2830809676285, 8911643119525
Offset: 1

Views

Author

R. H. Hardin Feb 19 2012

Keywords

Comments

Column 5 of A207729

Examples

			Some solutions for n=4
..1..0..1..1..1....1..0..1..1..1....1..0..1..1..0....0..0..1..1..0
..1..0..1..1..0....0..1..1..1..1....1..0..1..1..1....1..0..1..1..0
..1..0..1..1..0....0..0..1..1..1....0..0..1..1..0....0..1..1..1..1
..0..1..1..0..1....1..0..1..1..1....0..1..1..0..0....0..0..1..1..0
		

Formula

Empirical: a(n) = 4*a(n-1) -3*a(n-2) +10*a(n-3) -27*a(n-4) -6*a(n-5) -15*a(n-6) +51*a(n-7) +41*a(n-8) +31*a(n-9) -51*a(n-10) -29*a(n-11) -27*a(n-12) +15*a(n-13) +6*a(n-14) +3*a(n-15) -4*a(n-16) +a(n-17) +a(n-19)

A207727 Number of nX6 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

25, 625, 2209, 10609, 60025, 277729, 1247689, 5890329, 27426169, 125776225, 580858201, 2686867225, 12388803025, 57136775089, 263724358681, 1216770043329, 5612971227241, 25896730187689, 119479087561201, 551206670239681
Offset: 1

Views

Author

R. H. Hardin Feb 19 2012

Keywords

Comments

Column 6 of A207729

Examples

			Some solutions for n=4
..1..1..1..1..0..1....0..0..1..1..0..1....0..1..1..1..1..0....0..0..1..1..0..0
..1..1..1..1..1..1....1..1..1..1..0..0....1..1..1..1..1..1....1..0..1..1..1..1
..1..1..1..0..0..1....0..0..1..1..0..0....0..0..1..1..0..0....0..0..1..1..0..0
..1..1..1..0..0..1....0..0..1..1..0..0....0..0..1..1..0..0....0..1..1..1..0..0
		

Formula

Empirical: a(n) = 6*a(n-1) -7*a(n-2) +31*a(n-3) -128*a(n-4) -30*a(n-5) -116*a(n-6) +788*a(n-7) +798*a(n-8) +678*a(n-9) -2778*a(n-10) -1872*a(n-11) -1842*a(n-12) +3336*a(n-13) +1554*a(n-14) +378*a(n-15) -2736*a(n-16) +912*a(n-17) +312*a(n-18) +1590*a(n-19) -540*a(n-20) -228*a(n-21) -222*a(n-22) +210*a(n-23) -86*a(n-24) +24*a(n-25) -38*a(n-26) +8*a(n-27) -a(n-28) -a(n-30) +a(n-31)

A207728 Number of nX7 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

40, 1600, 6016, 33063, 211680, 1029231, 4799749, 23473944, 111527152, 517774120, 2415619129, 11251097760, 52094413065, 240990441237, 1114766044504, 5150494925352, 23781871171576, 109797744696883, 506801727014800
Offset: 1

Views

Author

R. H. Hardin Feb 19 2012

Keywords

Comments

Column 7 of A207729

Examples

			Some solutions for n=4
..1..1..1..1..1..0..1....0..0..1..1..1..1..1....1..0..1..1..1..0..1
..1..0..1..1..0..0..1....1..1..1..1..0..0..1....0..1..1..1..1..0..1
..0..0..1..1..0..0..1....0..0..1..1..0..0..1....0..0..1..1..0..1..1
..0..1..1..0..1..1..0....0..0..1..1..1..0..1....0..0..1..1..0..0..1
		

Formula

Empirical: a(n) = 6*a(n-1) -7*a(n-2) +31*a(n-3) -128*a(n-4) -30*a(n-5) -116*a(n-6) +788*a(n-7) +798*a(n-8) +678*a(n-9) -2778*a(n-10) -1872*a(n-11) -1842*a(n-12) +3336*a(n-13) +1554*a(n-14) +378*a(n-15) -2736*a(n-16) +912*a(n-17) +312*a(n-18) +1590*a(n-19) -540*a(n-20) -228*a(n-21) -222*a(n-22) +210*a(n-23) -86*a(n-24) +24*a(n-25) -38*a(n-26) +8*a(n-27) -a(n-28) -a(n-30) +a(n-31)

A207731 Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

9, 81, 189, 441, 2163, 10609, 33063, 103041, 418263, 1697809, 5875227, 20331081, 77333859, 294156801, 1057136187, 3799119769, 14123193995, 52502848225, 191262879795, 696752470089, 2569117858827, 9473043664561, 34677617171731
Offset: 1

Views

Author

R. H. Hardin Feb 19 2012

Keywords

Comments

Row 4 of A207729

Examples

			Some solutions for n=4
..1..0..1..1....1..1..1..0....0..0..1..1....1..1..0..1....1..1..0..0
..1..1..1..1....0..1..1..1....0..1..1..1....1..1..0..1....1..1..0..1
..0..0..1..1....0..1..1..0....1..0..1..1....1..0..0..1....1..1..1..0
..0..0..1..1....1..1..0..0....0..0..1..1....1..0..0..1....1..1..0..0
		

Formula

Empirical: a(n) = a(n-1) +12*a(n-3) +98*a(n-4) +12*a(n-5) +34*a(n-6) -230*a(n-7) -1980*a(n-8) -508*a(n-9) +340*a(n-10) +840*a(n-11) +9800*a(n-12) +3000*a(n-13) +2000*a(n-15) -10000*a(n-16)

A207732 Number of 5Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

14, 196, 490, 1225, 8575, 60025, 211680, 746496, 4078944, 22287841, 90968949, 371294361, 1833291198, 9052000164, 39384126042, 171355430401, 810254854919, 3831293402161, 17143608557024, 76711252182016, 355989323916384
Offset: 1

Views

Author

R. H. Hardin Feb 19 2012

Keywords

Comments

Row 5 of A207729

Examples

			Some solutions for n=4
..0..1..1..1....1..0..1..1....1..1..1..0....0..0..1..1....0..1..1..1
..1..0..1..1....0..1..1..1....1..1..0..1....1..0..1..1....1..0..1..1
..0..0..1..1....0..0..1..1....1..1..0..0....0..0..1..1....0..0..1..1
..0..0..1..1....0..0..1..1....1..1..1..0....0..0..1..1....0..1..1..1
..1..0..0..1....0..1..1..1....1..0..0..1....0..0..1..1....1..0..0..1
		

Formula

Empirical: a(n) = a(n-1) +21*a(n-3) +285*a(n-4) +40*a(n-5) +116*a(n-6) -1248*a(n-7) -17520*a(n-8) -5440*a(n-9) +3712*a(n-10) +13824*a(n-11) +291840*a(n-12) +102400*a(n-13) +131072*a(n-15) -1048576*a(n-16)

A207733 Number of 6Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 1 1 and 1 0 1 vertically.

Original entry on oeis.org

21, 441, 1113, 2809, 27931, 277729, 1029231, 3814209, 27996255, 205492225, 919461235, 4114067881, 26135084283, 166026096369, 818513711715, 4035297528025, 23843629466995, 140886430854481, 730455853771371
Offset: 1

Views

Author

R. H. Hardin Feb 19 2012

Keywords

Comments

Row 6 of A207729

Examples

			Some solutions for n=4
..1..0..0..1....1..0..1..1....1..1..0..1....1..0..1..1....0..1..1..0
..1..0..0..1....0..1..1..1....1..0..1..1....0..1..1..1....0..1..1..1
..1..1..0..1....0..0..1..1....1..0..0..1....0..0..1..1....0..1..1..0
..1..0..0..1....1..0..1..1....1..0..0..1....1..0..1..1....1..1..1..0
..1..0..0..1....0..0..1..1....1..1..0..1....0..1..1..1....0..1..1..0
..1..0..0..1....0..0..1..1....1..0..0..1....0..0..1..1....0..1..1..0
		

Formula

Empirical: a(n) = a(n-1) +32*a(n-3) +670*a(n-4) +84*a(n-5) +270*a(n-6) -4602*a(n-7) -97188*a(n-8) -30636*a(n-9) +21060*a(n-10) +124488*a(n-11) +4076280*a(n-12) +1423656*a(n-13) +2847312*a(n-15) -37015056*a(n-16)
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