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.

A262326 Number of (n+1) X (2+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits.

Original entry on oeis.org

3, 5, 15, 33, 99, 261, 783, 2241, 6723, 19845, 59535, 177633, 532899, 1595781, 4787343, 14353281, 43059843, 129153285, 387459855, 1162300833, 3486902499, 10460471301, 31381413903, 94143533121, 282430599363, 847289672325
Offset: 1

Views

Author

R. H. Hardin, Sep 18 2015

Keywords

Comments

Column 2 of A262332.

Examples

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

Crossrefs

Cf. A262332.

Formula

Empirical: a(n) = 3*a(n-1) + 3*a(n-2) - 9*a(n-3).
Conjectures from Colin Barker, Mar 20 2018: (Start)
G.f.: x*(3 - 4*x - 9*x^2) / ((1 - 3*x)*(1 - 3*x^2)).
a(n) = 2*3^(n/2-1) + 3^(n-1) for n even.
a(n) = 2*3^((n-3)/2+1) + 3^(n-1) for n odd.
(End)

A262325 Number of (n+1)X(n+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits.

Original entry on oeis.org

2, 5, 90, 2399, 570922, 394241389, 1456404454010, 19392931688071671, 1134083007177482717802, 256890679674803015904974405, 239672757231397671662393429466490
Offset: 1

Views

Author

R. H. Hardin, Sep 18 2015

Keywords

Comments

Diagonal of A262332.

Examples

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

Crossrefs

Cf. A262332.

A262327 Number of (n+1) X (3+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits.

Original entry on oeis.org

6, 15, 90, 351, 2106, 10935, 65610, 378351, 2270106, 13482855, 80897130, 484142751, 2904856506, 17417978775, 104507872650, 626946793551, 3761680761306, 22569180586695, 135415083520170, 812482365290751, 4874894191744506
Offset: 1

Views

Author

R. H. Hardin, Sep 18 2015

Keywords

Examples

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

Crossrefs

Column 3 of A262332.

Formula

Empirical: a(n) = 6*a(n-1) + 9*a(n-2) - 54*a(n-3).
Conjectures from Colin Barker, Dec 31 2018: (Start)
G.f.: 3*x*(2 - 7*x - 18*x^2) / ((1 - 3*x)*(1 + 3*x)*(1 - 6*x)).
a(n) = 3^(n-2)*(14 + 2^(2+n)) / 2 for n even.
a(n) = 3^(n-2)*(28 + 2^(2+n)) / 2 for n odd.
(End)

A262328 Number of (n+1) X (4+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits.

Original entry on oeis.org

11, 33, 351, 2399, 26131, 252097, 2767631, 29452071, 323841891, 3532758473, 38856792031, 426525918799, 4691681673011, 51580839266577, 567386112244911, 6240392439847991, 68644221256999171, 755059969459250713
Offset: 1

Views

Author

R. H. Hardin, Sep 18 2015

Keywords

Examples

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

Crossrefs

Column 4 of A262332.

Formula

Empirical: a(n) = 11*a(n-1) + 48*a(n-2) - 528*a(n-3) - 579*a(n-4) + 6369*a(n-5) + 1612*a(n-6) - 17732*a(n-7).
Empirical g.f.: x*(11 - 88*x - 540*x^2 + 2762*x^3 + 6687*x^4 - 16120*x^5 - 17732*x^6) / ((1 - 2*x)*(1 + 2*x)*(1 - 11*x)*(1 - 13*x^2)*(1 - 31*x^2)). - Colin Barker, Dec 31 2018

A262329 Number of (n+1)X(5+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits.

Original entry on oeis.org

22, 99, 2106, 26131, 570922, 10789339, 237172426, 5028462531, 110616890922, 2411745951979, 53057962551946, 1164684632805331, 25623040149388522, 563395838251985019, 12394707380225550666, 272646042792758242531
Offset: 1

Views

Author

R. H. Hardin, Sep 18 2015

Keywords

Comments

Column 5 of A262332.

Examples

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

Crossrefs

Cf. A262332.

Formula

Empirical: a(n) = 22*a(n-1) +215*a(n-2) -4730*a(n-3) -14143*a(n-4) +311146*a(n-5) +364285*a(n-6) -8014270*a(n-7) -3615956*a(n-8) +79551032*a(n-9) +9486400*a(n-10) -208700800*a(n-11)

A262330 Number of (n+1) X (6+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits.

Original entry on oeis.org

43, 261, 10935, 252097, 10789339, 394241389, 16940254423, 699094613961, 30056993215803, 1279198648576981, 55003871225837815, 2359070696262035857, 101439297012081117979, 4359072407628680510589, 187439773845177573589143
Offset: 1

Views

Author

R. H. Hardin, Sep 18 2015

Keywords

Comments

Column 6 of A262332.

Examples

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

Crossrefs

Cf. A262332.

Formula

Empirical: a(n) = 43*a(n-1) +793*a(n-2) -34099*a(n-3) -191667*a(n-4) +8241681*a(n-5) +20015927*a(n-6) -860684861*a(n-7) -980560940*a(n-8) +42164120420*a(n-9) +22309346640*a(n-10) -959301905520*a(n-11) -209959392832*a(n-12) +9028253891776*a(n-13) +540712883200*a(n-14) -23250653977600*a(n-15).

A262331 Number of (n+1)X(7+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits.

Original entry on oeis.org

86, 783, 65610, 2767631, 237172426, 16940254423, 1456404454010, 119519290640511, 10278397804194666, 873639089311509863, 75132812815390491610, 6442513290262072850191, 554056059394660086575306
Offset: 1

Views

Author

R. H. Hardin, Sep 18 2015

Keywords

Comments

Column 7 of A262332.

Examples

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

Crossrefs

Cf. A262332.

Formula

Empirical: a(n) = 86*a(n-1) +3252*a(n-2) -279672*a(n-3) -3329646*a(n-4) +286349556*a(n-5) +1544583660*a(n-6) -132834194760*a(n-7) -365579378025*a(n-8) +31439826510150*a(n-9) +46337467429704*a(n-10) -3985022198954544*a(n-11) -3102790005466128*a(n-12) +266839940470087008*a(n-13) +99548995158787584*a(n-14) -8561213583655732224*a(n-15) -1170690303846912000*a(n-16) +100679366130834432000*a(n-17) +3277061542543360000*a(n-18) -281827292658728960000*a(n-19)
Showing 1-7 of 7 results.