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.

A204699 Number of n X 2 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..2 introduced in row major order.

Original entry on oeis.org

2, 14, 96, 726, 5400, 40344, 301056, 2247264, 16773504, 125199744, 934502400, 6975223296, 52063770624, 388609284096, 2900619165696, 21650516238336, 161601653145600, 1206211160408064, 9003282670288896, 67201416721465344
Offset: 1

Views

Author

R. H. Hardin, Jan 18 2012

Keywords

Comments

Column 2 of A204705.

Examples

			Some solutions for n=5:
..0..0....0..0....0..1....0..1....0..1....0..1....0..0....0..1....0..0....0..1
..0..1....0..1....1..1....2..0....2..0....0..2....0..1....0..2....1..2....0..0
..2..0....2..1....0..2....0..1....1..2....2..0....2..0....1..1....0..2....2..0
..1..2....2..2....2..2....2..2....2..0....0..2....1..0....1..2....1..0....0..2
..0..2....0..0....1..0....2..1....0..1....1..0....0..2....2..1....2..1....0..0
		

Crossrefs

Cf. A204705.

Formula

Empirical: a(n) = 6*a(n-1) + 12*a(n-2) - 8*a(n-3) for n>5.
Empirical g.f.: 2*x*(1 - 2*x)*(1 + 3*x - x^3) / ((1 + 2*x)*(1 - 8*x + 4*x^2)). - Colin Barker, Feb 23 2018

A204700 Number of nX3 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..2 introduced in row major order.

Original entry on oeis.org

4, 96, 1417, 22869, 362020, 5767683, 91733605, 1459710274, 23224443905, 369522237415, 5879375305236, 93545539546075, 1488382733670257, 23681339437114202, 376788704103588493, 5995004229216188035
Offset: 1

Views

Author

R. H. Hardin Jan 18 2012

Keywords

Comments

Column 3 of A204705

Examples

			Some solutions for n=5
..0..1..0....0..0..1....0..1..2....0..0..1....0..1..0....0..0..1....0..0..1
..2..1..2....2..2..0....0..0..1....1..2..2....0..1..1....1..0..1....2..0..1
..2..2..1....0..2..1....2..2..1....2..1..2....1..0..2....2..1..2....2..1..2
..0..1..1....2..0..1....1..2..2....2..2..0....1..2..2....0..2..2....1..2..1
..0..0..2....2..0..2....0..0..1....0..1..1....2..0..0....2..0..0....0..2..1
		

Formula

Empirical: a(n) = 9*a(n-1) +117*a(n-2) -24*a(n-3) -1482*a(n-4) +884*a(n-5) +6805*a(n-6) -7217*a(n-7) +875*a(n-8) -9444*a(n-9) +23926*a(n-10) -157560*a(n-11) +235676*a(n-12) +268960*a(n-13) -735296*a(n-14) +199456*a(n-15) +747264*a(n-16) -760384*a(n-17) -340800*a(n-18) +784192*a(n-19) -38208*a(n-20) -346880*a(n-21) +138880*a(n-22) +50176*a(n-23) -91904*a(n-24) +17408*a(n-25) +25600*a(n-26) -8192*a(n-27) -4096*a(n-28) for n>31

A204701 Number of nX4 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..2 introduced in row major order.

Original entry on oeis.org

11, 726, 22869, 835135, 29846373, 1074195735, 38585324821, 1386815731346, 49835668719324, 1790952554181415, 64360800888516224, 2312920275315600518, 83118816237627091277, 2987020411865810161864, 107343805323748931471929
Offset: 1

Views

Author

R. H. Hardin Jan 18 2012

Keywords

Comments

Column 4 of A204705

Examples

			Some solutions for n=5
..0..1..0..2....0..1..2..0....0..1..0..2....0..1..0..1....0..1..2..2
..2..2..0..1....1..2..2..0....1..2..2..1....2..2..1..0....0..0..1..2
..2..0..1..1....0..1..1..2....1..0..1..1....1..1..0..0....1..2..2..0
..0..1..0..2....0..1..2..1....0..0..2..0....2..0..0..1....1..0..0..1
..1..2..2..1....2..2..0..0....0..2..0..0....0..1..1..0....2..2..1..2
		

A204702 Number of nX5 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..2 introduced in row major order.

Original entry on oeis.org

30, 5400, 362020, 29846373, 2389914827, 192759130113, 15521787839696, 1250634888842984, 100749784360671667, 8116764740949394264, 653904134820543785397, 52680223968250151357189, 4244049256144093743987455
Offset: 1

Views

Author

R. H. Hardin Jan 18 2012

Keywords

Comments

Column 5 of A204705

Examples

			Some solutions for n=5
..0..0..1..2..0....0..0..1..2..2....0..0..1..0..0....0..0..1..2..0
..1..2..1..2..1....2..1..2..1..1....1..2..1..0..0....1..1..2..0..2
..2..1..0..0..1....1..2..1..1..2....2..0..0..2..1....2..2..1..2..2
..1..1..2..1..2....1..1..0..2..2....2..1..1..2..1....2..1..0..0..1
..2..2..1..1..0....2..2..0..1..0....0..0..1..0..2....0..1..0..1..0
		

A204703 Number of nX6 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..2 introduced in row major order.

Original entry on oeis.org

82, 40344, 5767683, 1074195735, 192759130113, 34925753412578, 6319625580942184, 1144097011453760287, 207096410275997210933, 37489155843579834602268, 6786272895764958062549631
Offset: 1

Views

Author

R. H. Hardin Jan 18 2012

Keywords

Comments

Column 6 of A204705

Examples

			Some solutions for n=5
..0..1..0..0..1..0....0..0..1..2..0..2....0..0..1..2..0..1....0..0..1..2..2..0
..0..0..1..2..2..0....1..0..2..1..2..1....0..2..2..1..1..2....1..0..0..1..2..1
..2..1..1..2..0..1....2..2..1..2..0..0....2..1..2..0..2..1....0..1..1..2..0..0
..2..2..0..1..2..2....2..2..0..0..1..1....2..1..1..0..1..2....0..0..2..1..0..2
..1..0..0..1..2..0....0..0..1..2..0..2....0..2..1..2..0..2....1..1..2..0..2..2
		

A204698 Number of n X n 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..2 introduced in row major order.

Original entry on oeis.org

1, 14, 1417, 835135, 2389914827, 34925753412578, 2568926644225402978, 954699753721419299486986
Offset: 1

Views

Author

R. H. Hardin Jan 18 2012

Keywords

Comments

Diagonal of A204705

Examples

			Some solutions for n=5
..0..0..1..2..0....0..0..1..2..0....0..0..1..2..2....0..1..0..2..1
..1..1..2..0..2....1..2..1..2..1....2..2..1..1..2....2..2..1..1..0
..2..2..1..2..2....2..1..0..0..1....1..0..0..1..0....1..1..0..0..2
..2..1..0..0..1....1..1..2..1..2....1..1..2..0..2....0..0..2..0..0
..0..1..0..1..0....2..2..1..1..0....2..2..0..1..1....0..1..2..1..1
		

A204704 Number of nX7 0..2 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..2 introduced in row major order.

Original entry on oeis.org

224, 301056, 91733605, 38585324821, 15521787839696, 6319625580942184, 2568926644225402978, 1044792211767082026764, 424880469013125627760792, 172792044105478879279518350, 70270849522277745874734015748
Offset: 1

Views

Author

R. H. Hardin Jan 18 2012

Keywords

Comments

Column 7 of A204705

Examples

			Some solutions for n=5
..0..0..1..1..2..2..0....0..1..0..2..1..2..2....0..0..1..0..2..2..1
..2..2..0..1..2..2..0....1..1..0..1..1..0..0....2..0..0..2..0..0..2
..1..0..0..2..0..1..1....2..0..1..2..0..0..1....2..2..1..1..0..2..2
..1..0..1..2..2..0..0....1..2..0..2..2..1..0....0..1..0..1..2..0..0
..0..1..0..0..1..1..2....0..1..0..1..1..0..1....1..0..2..0..2..0..1
		
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