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 1-7 of 7 results.

A198179 Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4.

Original entry on oeis.org

0, 4, 3, 8, 16, 21, 56, 70, 171, 256, 516, 905, 1622, 3048, 5293, 9992, 17564, 32517, 58330, 106144, 192767, 348188, 634426, 1145535, 2084360, 3771658, 6847617, 12413706, 22507930, 40835531, 74015802, 134288434, 243440863, 441575714
Offset: 1

Views

Author

R. H. Hardin, Oct 21 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 0's.
Column 2 of A198185.

Examples

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

Crossrefs

Cf. A198185.

Formula

Empirical: a(n) = 3*a(n-2) +2*a(n-3) -2*a(n-4) -2*a(n-5) +4*a(n-7) -a(n-8) -3*a(n-9).
Empirical g.f.: x^2*(4 + 3*x - 4*x^2 - x^3 - x^4 + 6*x^5 - 3*x^6 - 7*x^7) / ((1 - x)*(1 + x - 2*x^2 - 4*x^3 - 2*x^4 - 4*x^7 - 3*x^8)). - Colin Barker, May 14 2018

A198180 Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4.

Original entry on oeis.org

1, 3, 9, 25, 77, 148, 395, 866, 2346, 5663, 14065, 34309, 84252, 208413, 513352, 1266410, 3117377, 7679699, 18927327, 46639092, 114949605, 283220762, 697929906, 1719783577, 4237987789, 10443340285, 25734497336, 63415169957, 156267786924
Offset: 1

Views

Author

R. H. Hardin Oct 21 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 0's
Column 3 of A198185

Examples

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

Formula

Empirical: a(n) = a(n-1) +3*a(n-2) -a(n-3) +3*a(n-4) +14*a(n-5) -a(n-6) -13*a(n-7) -17*a(n-8) -43*a(n-9) -73*a(n-10) -111*a(n-11) -70*a(n-12) -49*a(n-13) +87*a(n-14) +274*a(n-15) +424*a(n-16) +337*a(n-17) +389*a(n-18) +202*a(n-19) +184*a(n-20) -420*a(n-21) -643*a(n-22) -580*a(n-23) -287*a(n-24) -116*a(n-25) -426*a(n-26) -5*a(n-27) +80*a(n-28) +414*a(n-29) +294*a(n-30) +24*a(n-31) -12*a(n-32) -72*a(n-33) -30*a(n-34) +4*a(n-36) +4*a(n-37)

A198181 Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4.

Original entry on oeis.org

2, 8, 25, 59, 331, 883, 3485, 12030, 43774, 155664, 540628, 1936313, 6871687, 24471790, 86551688, 306708029, 1089956129, 3870392120, 13733968845, 48703981505, 172844148554, 613561265167, 2177517194687, 7726401450405
Offset: 1

Views

Author

R. H. Hardin Oct 21 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 0's
Column 4 of A198185

Examples

			Some solutions containing all values 0 to 4 for n=5
..0..1..2..1....1..2..1..0....1..2..1..0....0..1..1..2....1..0..1..2
..3..0..3..0....0..3..0..3....0..3..0..3....1..2..0..1....2..3..0..1
..0..4..0..1....3..0..4..0....1..0..4..0....1..0..4..0....1..0..4..0
..3..0..3..2....0..3..0..3....2..3..0..1....2..3..0..1....0..3..0..3
..0..3..0..1....1..2..1..0....1..0..1..2....1..0..1..2....1..2..1..0
		

A198182 Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4.

Original entry on oeis.org

1, 16, 77, 331, 2033, 8298, 48958, 216307, 1155412, 5522239, 28200527, 139401115, 695721892, 3477106364, 17307490471, 86498278609, 430707067503, 2150928384789, 10722364479972, 53497634923663, 266813770707004, 1330929200315097
Offset: 1

Views

Author

R. H. Hardin Oct 21 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 0's
Column 5 of A198185

Examples

			Some solutions containing all values 0 to 4 for n=4
..0..3..0..1..2....1..2..1..0..1....0..1..1..2..1....1..2..1..1..0
..3..0..4..0..1....0..3..0..3..2....1..2..0..3..0....0..3..0..2..1
..0..3..0..2..1....1..0..4..0..1....1..0..4..0..1....3..0..4..0..1
..1..2..1..1..0....2..1..0..3..0....2..1..0..1..2....0..3..0..1..2
		

A198183 Number of nX6 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4.

Original entry on oeis.org

1, 21, 148, 883, 8298, 51688, 395340, 2639341, 19059216, 135044844, 958174742, 6800519266, 48283678834, 342710822044, 2431565681788, 17263106688089, 122543913785532, 869732001977147, 6173405546650902, 43819646823646105
Offset: 1

Views

Author

R. H. Hardin Oct 21 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 0's
Column 6 of A198185

Examples

			Some solutions containing all values 0 to 4 for n=4
..2..1..0..3..0..1....1..2..0..3..0..1....0..2..1..0..3..0....2..1..1..2..1..0
..1..0..4..0..3..2....0..1..3..0..3..2....1..1..0..4..0..1....1..0..3..0..1..2
..0..3..0..4..0..1....2..1..0..4..0..1....2..0..3..0..3..2....0..3..0..4..0..1
..1..2..1..0..3..0....1..0..3..0..3..0....1..1..2..1..0..1....1..2..1..0..3..0
		

A198184 Number of nX7 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4.

Original entry on oeis.org

3, 56, 395, 3485, 48958, 395340, 4522496, 41084248, 441157382, 4292509761, 44051823241, 438360876506, 4438621935572, 44610898968447, 449562512780134, 4527350842044875, 45564682527974566, 459054827920170371
Offset: 1

Views

Author

R. H. Hardin Oct 21 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 0's
Column 7 of A198185

Examples

			Some solutions containing all values 0 to 4 for n=4
..1..2..1..0..1..1..0....2..1..0..3..0..3..0....1..0..3..0..3..0..1
..0..3..0..1..2..2..1....1..0..1..0..4..0..3....2..1..0..4..0..3..2
..1..0..4..0..3..0..1....1..2..2..3..0..3..0....0..1..3..0..3..0..1
..2..1..0..3..0..1..2....0..1..1..0..1..2..1....1..2..0..1..2..1..0
		

A198178 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 0,2,1,0,0 for x=0,1,2,3,4.

Original entry on oeis.org

1, 4, 9, 59, 2033, 51688, 4522496, 559601114, 174674654015
Offset: 1

Views

Author

R. H. Hardin Oct 21 2011

Keywords

Comments

Every 0 is next to 0 0's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 0's
Diagonal of A198185

Examples

			Some solutions for n=4
..0..2..1..1....0..3..0..1....1..0..3..0....1..0..2..1....1..0..1..2
..1..1..0..2....1..0..3..2....2..3..0..1....2..1..1..0....2..1..0..1
..2..0..1..1....2..1..0..1....1..0..1..2....2..1..0..1....0..1..1..0
..1..1..2..0....0..1..2..1....1..2..1..0....1..0..1..2....1..2..2..1
		
Showing 1-7 of 7 results.