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.

A268802 Number of n X n 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

3, 34, 332, 5848, 195384, 12432856, 1508087180, 348686105792, 154172619407288, 130573457756588328, 212323461305457440492, 663970589813116610557692, 3999438097971983178736358520, 46462227980008803491191644654968
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Diagonal of A268809.

Examples

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

Crossrefs

Cf. A268809.

A268803 Number of n X 2 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

9, 34, 104, 290, 772, 1972, 4914, 12010, 28922, 68836, 162274, 379524, 881712, 2036734, 4681646, 10714994, 24430816, 55516546, 125777028, 284188780, 640549034, 1440572818, 3233256010, 7243375068, 16199546178, 36172883716
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Examples

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

Crossrefs

Column 2 of A268809.

Formula

Empirical: a(n) = 2*a(n-1) + 3*a(n-2) - 2*a(n-3) - 6*a(n-4) - 4*a(n-5) - a(n-6) for n>7.
Empirical g.f.: x*(9 + 16*x + 9*x^2 - 2*x^3 + 2*x^4 + 6*x^5 + 3*x^6) / (1 - x - 2*x^2 - x^3)^2. - Colin Barker, Jan 15 2019

A268804 Number of nX3 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

24, 104, 332, 1202, 4158, 14308, 48460, 162722, 541744, 1791504, 5889586, 19264864, 62738690, 203528858, 658003018, 2120809106, 6816832928, 21856821554, 69922091542, 223229394256, 711333766468, 2262803472594, 7186710244256
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 3 of A268809.

Examples

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

Crossrefs

Cf. A268809.

Formula

Empirical: a(n) = 2*a(n-1) +9*a(n-2) -2*a(n-3) -33*a(n-4) -42*a(n-5) -14*a(n-6) +10*a(n-7) +8*a(n-8) -a(n-10) for n>12

A268805 Number of nX4 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

60, 290, 1202, 5848, 28452, 135912, 640926, 2990786, 13835892, 63544542, 290056316, 1317009868, 5952527788, 26795651036, 120193389832, 537427198324, 2396207992178, 10656560102448, 47282655935580, 209348341875062
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 4 of A268809.

Examples

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

Crossrefs

Cf. A268809.

Formula

Empirical: a(n) = 2*a(n-1) +19*a(n-2) +10*a(n-3) -122*a(n-4) -320*a(n-5) -295*a(n-6) +8*a(n-7) +176*a(n-8) +20*a(n-9) -98*a(n-10) -6*a(n-11) +43*a(n-12) -6*a(n-13) -11*a(n-14) +6*a(n-15) -a(n-16) for n>19

A268806 Number of nX5 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

144, 772, 4158, 28452, 195384, 1316226, 8734264, 57302798, 372342650, 2400532536, 15373692036, 97900054556, 620374078660, 3914367133320, 24605301916568, 154148669247610, 962830699411796, 5997782979007294, 37271323919688010
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 5 of A268809.

Examples

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

Crossrefs

Cf. A268809.

Formula

Empirical: a(n) = 2*a(n-1) +41*a(n-2) +54*a(n-3) -509*a(n-4) -2182*a(n-5) -2830*a(n-6) +1766*a(n-7) +7914*a(n-8) +2584*a(n-9) -10583*a(n-10) -6092*a(n-11) +11506*a(n-12) +5348*a(n-13) -11688*a(n-14) -620*a(n-15) +9251*a(n-16) -4462*a(n-17) -3137*a(n-18) +4774*a(n-19) -2365*a(n-20) +338*a(n-21) +198*a(n-22) -106*a(n-23) +12*a(n-24) +4*a(n-25) -a(n-26) for n>29

A268807 Number of nX6 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

336, 1972, 14308, 135912, 1316226, 12432856, 115671422, 1062318610, 9657289546, 87052567448, 779167091050, 6932066063186, 61353778718298, 540579543332426, 4744132651089162, 41488807479780664, 361699301828001722
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 6 of A268809.

Examples

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

Crossrefs

Cf. A268809.

Formula

Empirical: a(n) = 2*a(n-1) +83*a(n-2) +210*a(n-3) -1918*a(n-4) -13444*a(n-5) -27431*a(n-6) +22868*a(n-7) +172414*a(n-8) +91292*a(n-9) -572846*a(n-10) -576908*a(n-11) +1569339*a(n-12) +1662464*a(n-13) -4129647*a(n-14) -2739590*a(n-15) +10005684*a(n-16) +128072*a(n-17) -18820309*a(n-18) +14239344*a(n-19) +18275195*a(n-20) -39512592*a(n-21) +16595129*a(n-22) +32600294*a(n-23) -63035320*a(n-24) +55225574*a(n-25) -27556538*a(n-26) +5959238*a(n-27) +1367780*a(n-28) -935764*a(n-29) -205936*a(n-30) +253428*a(n-31) -6946*a(n-32) -44268*a(n-33) +5192*a(n-34) +6896*a(n-35) -1085*a(n-36) -848*a(n-37) +74*a(n-38) +94*a(n-39) +3*a(n-40) -6*a(n-41) -a(n-42) for n>45

A268808 Number of nX7 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once.

Original entry on oeis.org

768, 4914, 48460, 640926, 8734264, 115671422, 1508087180, 19390335102, 246666802206, 3110082281974, 38924665296474, 484120668061458, 5988867204857378, 73740656947715536, 904257358969806890
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 7 of A268809.

Examples

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

Crossrefs

Cf. A268809.

Formula

Empirical recurrence of order 68 (see link above)
Showing 1-7 of 7 results.