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 1-6 of 6 results.

A220932 Equals two maps: number of n X 3 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 n X 3 array.

Original entry on oeis.org

2, 16, 92, 556, 3332, 19996, 119972, 719836, 4319012, 25914076, 155484452, 932906716, 5597440292, 33584641756, 201507850532, 1209047103196, 7254282619172, 43525695715036, 261154174290212, 1566925045741276
Offset: 1

Views

Author

R. H. Hardin, Dec 25 2012

Keywords

Comments

Column 3 of A220935.

Examples

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

Crossrefs

Cf. A220935.

Formula

Empirical: a(n) = 5*a(n-1) + 6*a(n-2).
Conjectures from Colin Barker, Mar 13 2018: (Start)
G.f.: 2*x*(1 + 3*x) / ((1 + x)*(1 - 6*x)).
a(n) = (2^n*3^(n+1) + 4) / 7 for n even.
a(n) = (2^n*3^(n+1) - 4) / 7 for n odd
(End)

A220933 Equals two maps: number of nX4 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 nX4 array.

Original entry on oeis.org

4, 52, 673, 9107, 123958, 1686304, 22931365, 311813067, 4239917031, 57652874111, 783943412638, 10659785895199, 144948006719997, 1970951840091756, 26800307525626867, 364421123267042408, 4955269821323438717
Offset: 1

Views

Author

R. H. Hardin Dec 25 2012

Keywords

Comments

Column 4 of A220935

Examples

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

Formula

Empirical: a(n) = 28*a(n-1) -296*a(n-2) +1804*a(n-3) -7384*a(n-4) +21847*a(n-5) -48816*a(n-6) +85558*a(n-7) -123954*a(n-8) +160701*a(n-9) -200185*a(n-10) +236867*a(n-11) -248056*a(n-12) +226758*a(n-13) -197374*a(n-14) +171224*a(n-15) -136118*a(n-16) +103073*a(n-17) -90758*a(n-18) +83397*a(n-19) -61987*a(n-20) +38070*a(n-21) -26150*a(n-22) +15689*a(n-23) -3389*a(n-24) -92*a(n-25) -312*a(n-26) +112*a(n-27) -16*a(n-28)

A220936 Equals two maps: number of 2Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 2Xn array.

Original entry on oeis.org

1, 4, 16, 52, 200, 792, 3080, 12164, 47827, 188078, 739654, 2908308, 11433623, 44951623, 176719636, 694738324, 2731215010, 10737125607, 42210368413, 165939449883, 652348443363, 2564539277676, 10081819289214, 39634040551712
Offset: 1

Views

Author

R. H. Hardin Dec 25 2012

Keywords

Comments

Row 2 of A220935

Examples

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

Formula

Empirical: a(n) = 8*a(n-1) -22*a(n-2) +36*a(n-3) -83*a(n-4) +180*a(n-5) -202*a(n-6) +134*a(n-7) -163*a(n-8) -148*a(n-9) +1102*a(n-10) -1964*a(n-11) +2361*a(n-12) -2806*a(n-13) +1954*a(n-14) +698*a(n-15) -6089*a(n-16) +12746*a(n-17) -16274*a(n-18) +16250*a(n-19) -15958*a(n-20) +11458*a(n-21) +1206*a(n-22) -9876*a(n-23) +17244*a(n-24) -3208*a(n-25) +14772*a(n-26) -4156*a(n-27) +26925*a(n-28) +6308*a(n-29) +50808*a(n-30) +12984*a(n-31) +97889*a(n-32) +17770*a(n-33) +128262*a(n-34) +38432*a(n-35) +149644*a(n-36) +109876*a(n-37) +157919*a(n-38) +178940*a(n-39) +130160*a(n-40) +199080*a(n-41) +94482*a(n-42) +171386*a(n-43) +61079*a(n-44) +118320*a(n-45) +49065*a(n-46) +54958*a(n-47) +32068*a(n-48) +15960*a(n-49) +13770*a(n-50) +6182*a(n-51) +4376*a(n-52) +1600*a(n-53) +766*a(n-54) +188*a(n-55) +28*a(n-56) -8*a(n-57)

A220934 Equals two maps: number of nX5 binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 nX5 array.

Original entry on oeis.org

7, 200, 5912, 172904, 4983202, 143495572, 4129000493, 118791182035, 3417440488681, 98313052773312, 2828261800424005, 81363108971612428, 2340643785326878730, 67335342944117783361, 1937094540263542667587
Offset: 1

Views

Author

R. H. Hardin Dec 25 2012

Keywords

Comments

Column 5 of A220935

Examples

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

A220937 Equals two maps: number of 3Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 3Xn array.

Original entry on oeis.org

1, 12, 92, 673, 5912, 48212, 395844, 3232729, 26184472, 211363254
Offset: 1

Views

Author

R. H. Hardin Dec 25 2012

Keywords

Comments

Row 3 of A220935

Examples

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

A220938 Equals two maps: number of 4Xn binary arrays indicating the locations of corresponding elements equal to exactly two of their horizontal and antidiagonal neighbors in a random 0..2 4Xn array.

Original entry on oeis.org

1, 37, 556, 9107, 172904, 2876430, 49406891
Offset: 1

Views

Author

R. H. Hardin Dec 25 2012

Keywords

Comments

Row 4 of A220935

Examples

			Some solutions for n=3
..0..0..1....0..0..0....0..0..0....0..0..1....0..0..1....0..1..0....0..1..1
..0..1..1....0..0..0....0..0..0....1..1..0....1..0..1....1..0..0....0..0..0
..0..0..1....0..1..0....0..1..0....0..1..1....1..0..0....0..1..1....0..1..1
..1..1..0....0..1..0....1..1..0....0..0..0....0..1..0....1..1..0....0..0..0
		
Showing 1-6 of 6 results.