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 1-5 of 5 results.

A245158 Number of length n 0..3 arrays with new values introduced in order from both ends.

Original entry on oeis.org

1, 1, 2, 4, 9, 23, 65, 199, 653, 2275, 8313, 31439, 121637, 477307, 1888721, 7509799, 29940861, 119550419, 477742889, 1909988479, 7637856725, 30546970411, 122178444417, 488693854679, 1954733475629, 7818845822083, 31275198738905
Offset: 1

Views

Author

R. H. Hardin, Jul 12 2014

Keywords

Examples

			Some solutions for n=7:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....0....1....0....1....1....1....1....1....1....1....0....0....1....1....1
..0....0....0....1....1....2....0....2....2....0....0....1....0....0....1....2
..0....1....0....1....0....0....1....2....1....2....2....0....0....0....2....1
..1....2....0....2....1....2....1....1....0....1....1....1....0....0....0....1
..0....1....0....1....0....1....0....0....0....1....0....0....0....1....1....0
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
		

Crossrefs

Column 3 of A245163.

Formula

Empirical: a(n) = 10*a(n-1) - 37*a(n-2) + 64*a(n-3) - 52*a(n-4) + 16*a(n-5) for n>6.
Conjectures from Colin Barker, Nov 03 2018: (Start)
G.f.: x*(1 - 9*x + 29*x^2 - 43*x^3 + 31*x^4 - 11*x^5) / ((1 - x)^2*(1 - 2*x)^2*(1 - 4*x)).
a(n) = (-64 - 27*2^(2+n) + 4^n + 12*(32+3*2^n)*n) / 576 for n>1.
(End)

A245159 Number of length n 0..4 arrays with new values introduced in order from both ends.

Original entry on oeis.org

1, 1, 2, 4, 9, 23, 65, 199, 654, 2296, 8568, 33794, 140039, 605869, 2718531, 12564289, 59419764, 285878342, 1392536354, 6842206084, 33819153429, 167827213315, 835048228437, 4162123757579, 20768689294634, 103709892420388
Offset: 1

Views

Author

R. H. Hardin, Jul 12 2014

Keywords

Examples

			Some solutions for n=7:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....1....0....1....0....1....0....1....1....0....1....1....0....1....0....0
..0....0....1....1....1....0....1....0....1....1....2....2....1....2....0....1
..1....2....2....2....1....1....0....2....0....2....0....1....1....1....0....0
..1....2....1....2....2....0....2....0....0....1....0....1....0....0....1....0
..0....1....0....1....1....0....1....1....1....1....1....0....1....1....1....1
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
		

Crossrefs

Column 4 of A245163.

Formula

Empirical: a(n) = 17*a(n-1) - 118*a(n-2) + 434*a(n-3) - 913*a(n-4) + 1097*a(n-5) - 696*a(n-6) + 180*a(n-7) for n>8.
Conjectures from Colin Barker, Nov 03 2018: (Start)
G.f.: x*(1 - 16*x + 103*x^2 - 346*x^3 + 656*x^4 - 710*x^5 + 425*x^6 - 124*x^7) / ((1 - x)^2*(1 - 2*x)^2*(1 - 3*x)^2*(1 - 5*x)).
a(n) = (-3375 - 525*2^(4+n) - 1300*3^n + 3*5^n + 100*(297+9*2^(2+n) + 2*3^n)*n) / 43200.
(End)

A245160 Number of length n 0..5 arrays with new values introduced in order from both ends.

Original entry on oeis.org

1, 1, 2, 4, 9, 23, 65, 199, 654, 2296, 8569, 33825, 140580, 612890, 2794159, 13280627, 65597882, 335521900, 1770176005, 9593485125, 53183385680, 300371056446, 1721926382427, 9987133305239, 58446578859494, 344361988828048
Offset: 1

Views

Author

R. H. Hardin, Jul 12 2014

Keywords

Examples

			Some solutions for n=7:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....1....1....1....1....1....1....1....0....1....0....1....1....1....1....0
..1....2....1....0....0....0....0....0....1....2....1....0....0....2....1....1
..0....2....0....0....2....1....0....1....2....2....2....0....1....2....2....2
..2....2....0....0....0....0....0....0....0....0....1....1....1....1....2....2
..1....1....1....0....1....1....1....0....1....1....0....0....0....0....1....1
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
		

Crossrefs

Column 5 of A245163.

Formula

Empirical: a(n) = 26*a(n-1) - 290*a(n-2) + 1820*a(n-3) - 7073*a(n-4) + 17618*a(n-5) - 28060*a(n-6) + 27480*a(n-7) - 14976*a(n-8) + 3456*a(n-9) for n>10.
Empirical g.f.: x*(1 - 25*x + 266*x^2 - 1578*x^3 + 5738*x^4 - 13236*x^5 + 19385*x^6 - 17565*x^7 + 9271*x^8 - 2381*x^9) / ((1 - x)^2*(1 - 2*x)^2*(1 - 3*x)^2*(1 - 4*x)^2*(1 - 6*x)). - Colin Barker, Nov 03 2018

A245161 Number of length n 0..6 arrays with new values introduced in order from both ends.

Original entry on oeis.org

1, 1, 2, 4, 9, 23, 65, 199, 654, 2296, 8569, 33825, 140581, 612933, 2795181, 13298407, 65851100, 338654554, 1805083341, 9952373825, 56645932971, 332111798479, 2000990363889, 12357518954759, 78010845456554, 501994699807228
Offset: 1

Views

Author

R. H. Hardin, Jul 12 2014

Keywords

Examples

			Some solutions for n=7:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....0....0....1....1....1....1....1....0....1....1....1....1....0....1....1
..0....1....1....1....1....0....1....0....0....2....2....2....1....0....0....1
..1....1....0....0....2....1....2....1....1....2....2....2....0....1....2....0
..0....0....1....1....1....0....1....2....1....0....1....2....0....1....1....0
..0....1....1....0....0....1....1....1....1....1....1....1....0....0....0....1
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
		

Crossrefs

Column 6 of A245163.

Formula

Empirical: a(n) = 37*a(n-1) - 605*a(n-2) + 5765*a(n-3) - 35523*a(n-4) + 148371*a(n-5) - 427775*a(n-6) + 849335*a(n-7) - 1134976*a(n-8) + 969292*a(n-9) - 474720*a(n-10) + 100800*a(n-11) for n>12.
Empirical g.f.: x*(1 - 36*x + 570*x^2 - 5230*x^3 + 30829*x^4 - 122268*x^5 + 332049*x^6 - 616386*x^7 + 767435*x^8 - 616428*x^9 + 296529*x^10 - 69446*x^11) / ((1 - x)^2*(1 - 2*x)^2*(1 - 3*x)^2*(1 - 4*x)^2*(1 - 5*x)^2*(1 - 7*x)). - Colin Barker, Nov 03 2018

A245162 Number of length n 0..7 arrays with new values introduced in order from both ends.

Original entry on oeis.org

1, 1, 2, 4, 9, 23, 65, 199, 654, 2296, 8569, 33825, 140581, 612933, 2795182, 13298464, 65852872, 338694406, 1805809431, 9963758843, 56805378239, 334156440067, 2025424520548, 12633195093794, 80976535864874, 532652296499548
Offset: 1

Views

Author

R. H. Hardin, Jul 12 2014

Keywords

Comments

Column 7 of A245163

Examples

			Some solutions for n=7
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....0....0....1....1....1....1....1....1....0....1....0....0....1....0....1
..0....0....1....1....0....1....2....2....1....1....1....1....0....0....0....1
..2....0....2....0....1....1....3....1....1....0....2....1....1....0....0....1
..0....1....1....1....1....0....2....1....1....0....1....1....1....1....0....0
..1....1....1....0....0....1....1....1....1....1....1....1....1....0....1....0
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
		

Formula

Empirical: a(n) = 50*a(n-1) -1127*a(n-2) +15148*a(n-3) -135303*a(n-4) +846930*a(n-5) -3816041*a(n-6) +12508144*a(n-7) -29761816*a(n-8) +50647520*a(n-9) -59753232*a(n-10) +46142208*a(n-11) -20839680*a(n-12) +4147200*a(n-13) for n>14
Showing 1-5 of 5 results.