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.

A268791 Number of n X n 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

0, 22, 248, 4800, 168740, 11138352, 1384570516, 325815151556, 145913571668076, 124768928833331732, 204377241703937153076, 642788798787566885184552, 3889478620658657294120765368, 45350632160719542617837369658508
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Diagonal of A268798.

Examples

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

Crossrefs

Cf. A268798.

A268792 Number of n X 2 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

3, 22, 78, 234, 652, 1714, 4360, 10820, 26366, 63346, 150482, 354196, 827310, 1919884, 4430664, 10175910, 23272918, 53029498, 120435100, 272714858, 615904208, 1387638220, 3119557838, 6999162874, 15675003042, 35046218020
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Examples

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

Crossrefs

Column 2 of A268798.

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*(3 + 16*x + 25*x^2 + 18*x^3 + 12*x^4 + 8*x^5 + 3*x^6) / (1 - x - 2*x^2 - x^3)^2. - Colin Barker, Jan 15 2019

A268793 Number of nX3 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

12, 78, 248, 950, 3384, 11948, 41248, 140698, 474472, 1586038, 5262024, 17348096, 56884272, 185647624, 603388088, 1953997896, 6307338900, 20300666174, 65169102416, 208712267048, 666993883320, 2127375490930, 6773070493400
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 3 of A268798.

Examples

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

Crossrefs

Cf. A268798.

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

A268794 Number of nX4 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

36, 234, 950, 4800, 23994, 117062, 561116, 2652936, 12405748, 57490444, 264428454, 1208522850, 5493284922, 24851601802, 111963916212, 502590509990, 2248738675490, 10032298715910, 44640056867750, 198161794087570
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 4 of A268798.

Examples

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

Crossrefs

Cf. A268798.

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

A268795 Number of nX5 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

96, 652, 3384, 23994, 168740, 1158904, 7801688, 51781418, 339641264, 2206871084, 14226779556, 91107781858, 580148670100, 3676143046622, 23194484120032, 145793482383084, 913349363853072, 5704743147188222, 35535874740219072
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 5 of A268798.

Examples

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

Crossrefs

Cf. A268798.

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

A268796 Number of nX6 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

240, 1714, 11948, 117062, 1158904, 11138352, 104971262, 974000420, 8927994302, 81031120788, 729449219322, 6521558348746, 57964319359808, 512593621373638, 4513059897036336, 39580897460175788, 345946165584055346
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 6 of A268798.

Examples

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

Crossrefs

Cf. A268798.

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

A268797 Number of nX7 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.

Original entry on oeis.org

576, 4360, 41248, 561116, 7801688, 104971262, 1384570516, 17967375416, 230262982692, 2921020155826, 36745483472428, 459003330021886, 5699362152372404, 70403795917829390, 865796392149477244
Offset: 1

Views

Author

R. H. Hardin, Feb 13 2016

Keywords

Comments

Column 7 of A268798.

Examples

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

Crossrefs

Cf. A268798.

Formula

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