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 13 results. Next

A208401 Number of n X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

1, 15, 10682, 163422914, 39216100214432, 146298576850884166522, 8484183047877022205116428184, 7648479804732030712438650610523878146, 107185313935414834818609318544471943157967376388
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2012

Keywords

Comments

Diagonal of A208408.

Examples

			Some solutions for n=4
..0..1..1..2....0..0..0..1....0..1..0..0....0..1..1..0....0..0..1..0
..0..1..0..0....0..1..1..0....2..0..3..0....0..0..2..0....2..0..1..2
..0..0..3..0....0..1..1..0....2..0..3..1....0..2..1..1....1..3..0..0
..1..1..2..0....0..0..0..1....1..2..0..2....3..1..0..0....1..3..2..2
		

Crossrefs

Cf. A208408.

A208402 Number of n X 2 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

2, 15, 187, 2795, 43947, 700075, 11188907, 178973355, 2863377067, 45813246635, 733008800427, 11728128223915, 187650001250987, 3002399818689195, 48038396293720747, 768614337478306475, 12297829386768001707
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2012

Keywords

Comments

Column 2 of A208408.

Examples

			Some solutions for n=4:
..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..1....0..0
..0..0....0..1....1..0....0..0....0..0....0..1....0..1....0..0....1..1....1..0
..1..1....0..0....0..2....0..1....1..2....1..0....0..0....1..0....0..0....2..0
..2..0....1..0....2..0....1..0....3..2....1..1....0..2....2..2....0..1....1..2
		

Crossrefs

Cf. A208408.

Formula

Empirical: a(n) = 21*a(n-1) - 84*a(n-2) + 64*a(n-3).
Conjectures from Colin Barker, Jul 02 2018: (Start)
G.f.: x*(2 - 27*x + 40*x^2) / ((1 - x)*(1 - 4*x)*(1 - 16*x)).
a(n) = (8 + 3*2^(1+2*n) + 16^n) / 24.
(End)

A208403 Number of n X 3 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

5, 182, 10682, 667478, 42012698, 2646531062, 166729574522, 10503950018198, 661748758909658, 41690171165650742, 2626480778916392762, 165468289040095516118, 10424502209304556920218, 656743639184636861807222
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2012

Keywords

Comments

Column 3 of A208408.

Examples

			Some solutions for n=4:
..0..0..0....0..0..0....0..0..0....0..0..0....0..1..1....0..0..0....0..0..0
..1..1..0....0..1..0....0..1..1....0..1..0....1..0..2....0..1..0....0..1..1
..0..1..0....1..2..1....1..0..0....0..1..1....3..0..1....2..1..1....2..0..2
..0..1..0....0..1..3....0..1..1....2..0..2....1..1..1....2..1..1....2..1..0
		

Crossrefs

Cf. A208408.

Formula

Empirical: a(n) = 70*a(n-1) - 441*a(n-2) for n>3.
Conjectures from Colin Barker, Jul 02 2018: (Start)
G.f.: x*(5 - 168*x + 147*x^2) / ((1 - 7*x)*(1 - 63*x)).
a(n) = (2/27)*7^(-1+n) * (27+4*9^n) for n>1.
(End)

A208404 Number of n X 4 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

15, 2698, 658450, 163422914, 40595679634, 10084768380770, 2505261257850802, 622357842865595522, 154606345205565641170, 38407360426219085921186, 9541169432411414821885426, 2370220528768971149166621890
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2012

Keywords

Comments

Column 4 of A208408.

Examples

			Some solutions for n=4
..0..0..1..2....0..1..0..0....0..0..0..1....0..1..1..1....0..0..0..1
..0..3..3..0....2..0..3..0....1..2..1..1....0..0..0..1....1..0..1..1
..1..0..1..2....2..0..3..1....0..2..0..3....0..1..0..0....2..2..1..0
..1..1..0..0....1..2..0..2....0..0..2..1....0..1..1..1....0..3..0..0
		

Crossrefs

Cf. A208408.

Formula

Empirical: a(n) = 262*a(n-1) - 3385*a(n-2) + 2868*a(n-3) - 576*a(n-4) for n>5.
Empirical g.f.: x*(15 - 1232*x + 2349*x^2 - 1276*x^3 + 192*x^4) / ((1 - 13*x + 4*x^2)*(1 - 249*x + 144*x^2)). - Colin Barker, Jul 02 2018

A208405 Number of nX5 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

51, 41914, 40883360, 40039156736, 39216100214432, 38410047476679936, 37620564383817645696, 36847308431734650845696, 36089946042522268966513152, 35348150537672718536490582016, 34621601954234065647421901637632
Offset: 1

Views

Author

R. H. Hardin Feb 26 2012

Keywords

Comments

Column 5 of A208408

Examples

			Some solutions for n=4
..0..0..1..0..2....0..0..0..0..0....0..0..0..1..2....0..0..1..0..0
..3..1..0..0..1....0..1..0..2..2....3..2..0..1..2....1..1..0..1..0
..1..1..1..2..2....2..2..3..2..2....1..1..1..0..2....0..1..1..0..2
..3..0..3..3..0....3..1..1..2..1....1..3..3..1..2....1..2..1..0..3
		

Formula

Empirical: a(n) = 1008*a(n-1) -28108*a(n-2) +138160*a(n-3) -223680*a(n-4) +168192*a(n-5) -55296*a(n-6) for n>7

A208406 Number of nX6 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

187, 658450, 2540446156, 9810325806914, 37884515848419250, 146298576850884166522, 564960990903273888822194, 2181708996196484728947116626, 8425102300382037852914721068050
Offset: 1

Views

Author

R. H. Hardin Feb 26 2012

Keywords

Comments

Column 6 of A208408

Examples

			Some solutions for n=4
..0..0..0..0..0..0....0..1..1..0..0..0....0..1..0..0..2..2....0..0..0..0..0..0
..1..2..1..0..1..3....0..1..1..0..2..1....1..2..1..1..3..2....0..1..1..0..2..1
..1..3..3..1..1..3....1..2..0..3..2..3....0..3..3..0..1..3....0..1..0..2..2..1
..0..1..0..0..1..0....3..0..0..2..1..3....2..1..1..2..1..1....0..3..1..0..1..0
		

Formula

Empirical: a(n) = 3934*a(n-1) -280797*a(n-2) +6155504*a(n-3) -54994340*a(n-4) +272040900*a(n-5) -839264272*a(n-6) +1746698176*a(n-7) -2573895744*a(n-8) +2742227712*a(n-9) -2077701120*a(n-10) +970113024*a(n-11) -191102976*a(n-12) for n>13

A208407 Number of nX7 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

715, 10370330, 157873031498, 2403711876698218, 36598079445605633928, 557229580446475130201608, 8484183047877022205116428184, 129177209027669581083328287797640, 1966807085374417176424317546443585928
Offset: 1

Views

Author

R. H. Hardin Feb 26 2012

Keywords

Comments

Column 7 of A208408

Examples

			Some solutions for n=4
..0..0..0..0..1..2..1....0..0..0..1..0..0..0....0..0..0..0..0..0..0
..1..1..0..2..1..3..3....1..0..2..2..1..1..2....0..1..0..1..0..2..1
..1..2..0..2..2..1..2....2..0..1..3..1..3..1....0..2..2..3..0..0..1
..0..0..1..0..2..2..0....0..3..3..3..2..1..3....0..3..3..3..3..1..3
		

A208409 Number of 2 X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

2, 15, 182, 2698, 41914, 658450, 10370330, 163422914, 2575668586, 40595679634, 639841707002, 10084768380770, 158949607034890, 2505261257850802, 39486313909133978, 622357842865595522, 9809203406810575786
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2012

Keywords

Comments

Row 2 of A208408.

Examples

			Some solutions for n=4:
..0..0..0..1....0..1..1..1....0..0..0..0....0..0..1..0....0..0..1..0
..1..1..0..0....0..0..0..1....1..0..2..2....0..0..0..0....2..0..1..2
		

Crossrefs

Cf. A208408.

Formula

Empirical: a(n) = 18*a(n-1) - 31*a(n-2) - 66*a(n-3) - 24*a(n-4) for n>6.
Empirical g.f.: x*(1 + x)*(2 - 23*x - 3*x^2 + 22*x^3 + 8*x^4) / ((1 - 3*x - 2*x^2)*(1 - 15*x - 12*x^2)). - Colin Barker, Jul 02 2018

A208410 Number of 3 X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

5, 187, 10682, 658450, 40883360, 2540446156, 157873031498, 9810914663050, 609693293454056, 37889020302613060, 2354590230800815490, 146324584692741696562, 9093252748398554214416, 565094688091663621180732
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2012

Keywords

Comments

Row 3 of A208408.

Examples

			Some solutions for n=4:
..0..0..0..0....0..0..1..0....0..1..1..1....0..1..1..1....0..0..0..0
..0..1..1..2....0..0..0..0....0..2..3..0....0..0..0..1....0..1..0..0
..0..1..0..0....1..1..1..0....1..1..1..1....0..1..0..0....1..2..3..2
		

Crossrefs

Cf. A208408.

Formula

Empirical: a(n) = 62*a(n-1) + 39*a(n-2) - 1790*a(n-3) - 4703*a(n-4) - 1254*a(n-5) + 3249*a(n-6) + 918*a(n-7) - 648*a(n-8) for n>10.
Empirical g.f.: x*(1 + x)*(2 - 23*x - 3*x^2 + 22*x^3 + 8*x^4) / ((1 - 3*x - 2*x^2)*(1 - 15*x - 12*x^2)). - Colin Barker, Jul 02 2018

A208411 Number of 4 X n 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

Original entry on oeis.org

15, 2795, 667478, 163422914, 40039156736, 9810325806914, 2403711876698218, 588954110860577394, 144304709913279198696, 35357337571782719886214, 8663205247528271356492160, 2122646395773319892200238358
Offset: 1

Views

Author

R. H. Hardin, Feb 26 2012

Keywords

Comments

Row 4 of A208408.

Examples

			Some solutions for n=4
..0..0..0..1....0..1..0..0....0..1..1..1....0..0..0..0....0..0..0..1
..1..2..1..1....2..0..3..0....0..0..0..1....0..1..1..2....0..1..1..0
..0..2..0..3....2..0..3..1....0..1..0..0....1..0..1..3....0..1..1..0
..0..0..2..1....1..2..0..2....0..1..1..1....1..3..3..1....0..0..0..1
		

Crossrefs

Cf. A208408.

Formula

Empirical: a(n) = 226*a(n-1) +4747*a(n-2) -18294*a(n-3) -739509*a(n-4) -1661510*a(n-5) +17227605*a(n-6) +10151090*a(n-7) -98711047*a(n-8) -11588022*a(n-9) +195980121*a(n-10) -44074854*a(n-11) -121060656*a(n-12) +71173728*a(n-13) -10077696*a(n-14) for n>16.
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