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.

A217631 Number of nX2 arrays of the minimum value of corresponding elements and their horizontal and vertical neighbors in a random 0..1 nX2 array.

Original entry on oeis.org

0, 2, 6, 16, 38, 98, 244, 614, 1542, 3872, 9726, 24426, 61348, 154078, 386974, 971904, 2440982, 6130642, 15397396, 38671286, 97124758, 243933408, 612650254, 1538699994, 3864517572, 9705918062, 24376870766, 61223660096, 153766108518
Offset: 0

Views

Author

R. H. Hardin Oct 09 2012

Keywords

Comments

Also, number of maximal independent sets in the 3-dimensional (2, 2, n) grid graph. [Euler et al.] - N. J. A. Sloane, Nov 21 2013
Column 2 of A217637.

Examples

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

Crossrefs

Formula

G.f. = (2*x+4*x^2+4*x^3)/(1-x-3*x^2-2*x^3). [Euler et al.] - N. J. A. Sloane, Nov 21 2013
Empirical: a(n) = a(n-1) + 3*a(n-2) + 2*a(n-3). (Follows from g.f. - N. J. A. Sloane, Nov 21 2013)

A217632 Number of nX3 arrays of the minimum value of corresponding elements and their horizontal and vertical neighbors in a random 0..1 nX3 array.

Original entry on oeis.org

0, 4, 16, 66, 244, 968, 3726, 14520, 56352, 218978, 850620, 3304624, 12837742, 49872976, 193747784, 752680930, 2924043092, 11359448344, 44129645550, 171436683864, 666004286592, 2587320999714, 10051331417116, 39047827550656
Offset: 0

Views

Author

R. H. Hardin Oct 09 2012

Keywords

Comments

Also, number of maximal independent sets in the 3-dimensional (2, 3, n) grid graph. [Euler et al.] - N. J. A. Sloane, Nov 21 2013
Column 3 of A217637.

Examples

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

Crossrefs

Cf. A217637.

Formula

Empirical: a(n) = 2*a(n-1) +9*a(n-2) -2*a(n-3) -17*a(n-4) -4*a(n-5) +8*a(n-6) -3*a(n-7) +a(n-8) -3*a(n-9) -2*a(n-10) +4*a(n-11)
Euler et al. give an explicit g.f. and recurrence, and so (presumably) prove this recurrence is correct. - N. J. A. Sloane, Nov 21 2013

A217633 Number of n X 4 arrays of the minimum value of corresponding elements and their horizontal and vertical neighbors in a random 0..1 n X 4 array.

Original entry on oeis.org

6, 38, 244, 1418, 8706, 52120, 315378, 1900838, 11472148, 69210290, 417586442, 2519466108, 15201104542, 91714930026, 553357475040, 3338651662490, 20143579337906, 121535200857060, 733276159043790, 4424182455856594, 26693068489330768, 161051201588069830, 971693816818476190
Offset: 1

Views

Author

R. H. Hardin, Oct 09 2012

Keywords

Examples

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

Crossrefs

Column 4 of A217637.

Formula

Empirical: a(n) = 4*a(n-1) +20*a(n-2) -29*a(n-3) -124*a(n-4) +55*a(n-5) +330*a(n-6) -57*a(n-7) -498*a(n-8) -291*a(n-9) +965*a(n-10) +676*a(n-11) -991*a(n-12) -659*a(n-13) +771*a(n-14) +610*a(n-15) -581*a(n-16) -78*a(n-17) -36*a(n-18) +32*a(n-19) -94*a(n-20) +32*a(n-21) +68*a(n-22) -16*a(n-23).

A217634 Number of nX5 arrays of the minimum value of corresponding elements and their horizontal and vertical neighbors in a random 0..1 nX5 array.

Original entry on oeis.org

10, 98, 968, 8706, 83074, 773348, 7272142, 68138974, 639248556, 5994907930, 56226693158, 527340415924, 4945869727454, 46386705274750, 435055533728012, 4080334184200118, 38268976277521222, 358920216579635816
Offset: 1

Views

Author

R. H. Hardin Oct 09 2012

Keywords

Comments

Column 5 of A217637

Examples

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

A217635 Number of nX6 arrays of the minimum value of corresponding elements and their horizontal and vertical neighbors in a random 0..1 nX6 array.

Original entry on oeis.org

16, 244, 3726, 52120, 773348, 11181454, 163361868, 2378097084, 34661572702, 505010822224, 7358779655656, 107224919634686, 1562394222954108, 22765852658001192, 331724751544038894, 4833609504204441184
Offset: 1

Views

Author

R. H. Hardin Oct 09 2012

Keywords

Comments

Column 6 of A217637

Examples

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

A217636 Number of nX7 arrays of the minimum value of corresponding elements and their horizontal and vertical neighbors in a random 0..1 nX7 array.

Original entry on oeis.org

26, 614, 14520, 315378, 7272142, 163361868, 3709621842, 83923710538, 1901055652804, 43046530809006, 974841850791586, 22075731493018104, 499920666839751010, 11321017480253759030, 256371943510592766924
Offset: 1

Views

Author

R. H. Hardin Oct 09 2012

Keywords

Comments

Column 7 of A217637

Examples

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

A217630 Number of n X n arrays of the minimum value of corresponding elements and their horizontal and vertical neighbors in a random 0..1 n X n array.

Original entry on oeis.org

2, 6, 66, 1418, 83074, 11181454, 3709621842, 2950299178242, 5681245408101350, 26398983976826626170
Offset: 1

Views

Author

R. H. Hardin Oct 09 2012

Keywords

Comments

Diagonal of A217637

Examples

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