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 1-3 of 3 results.

A250544 T(n,k) = number of (n+1)X(k+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

150, 1080, 1080, 6627, 10704, 6627, 36552, 79366, 79366, 36552, 187000, 491650, 644779, 491650, 187000, 905440, 2701872, 4169584, 4169584, 2701872, 905440, 4206453, 13657024, 23289547, 27240292, 23289547, 13657024, 4206453, 18933408
Offset: 1

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Author

R. H. Hardin, Nov 24 2014

Keywords

Comments

Peter Luschny remarks that the coefficients of the empirical recurrence relation for the column 1 are listed in the 9th row of A246117. - M. F. Hasler, Feb 11 2015

Examples

			Some solutions for n=2 k=4
..2..2..1..0..0....2..0..3..1..1....2..2..2..2..0....0..0..2..0..0
..2..3..2..2..2....0..0..3..2..2....2..2..2..2..0....1..1..3..1..1
..1..3..2..3..3....0..0..3..2..3....1..2..2..2..3....0..0..2..0..2
Table starts:
.......150.......1080........6627........36552........187000........905440
......1080......10704.......79366.......491650.......2701872......13657024
......6627......79366......644779......4169584......23289547.....117777788
.....36552.....491650.....4169584.....27240292.....151170400.....752602024
....187000....2701872....23289547....151170400.....824599694....4013192386
....905440...13657024...117777788....752602024....4013192386...19031828420
...4206453...64993652...555362165...3475227442...18064444143...83356429646
..18933408..295871112..2489782728..15210145612...76961701472..345394150196
..83153850.1302924116.10756619019..64036997144..315204675572.1375930596944
.358250280.5595784456.45218540866.262068107390.1254564769204.5328628464360
		

Crossrefs

Row/column 1 is A223069(n+1) and row/column 2 of A223071.
Row/column 2-7 are A250538 - A250543; diagonal is A250537.

Formula

Empirical for column k (k=2-7 recurrence also works for k=1):
k=1: a(n) = 16*a(n-1) -106*a(n-2) +376*a(n-3) -769*a(n-4) +904*a(n-5) -564*a(n-6) +144*a(n-7)
k=2: [order 16, see A250538]
k=3: [same order 16]
k=4: [same order 16]
k=5: [same order 16]
k=6: [same order 16]
k=7: [same order 16]

Extensions

Edited by M. F. Hasler, Feb 11 2015

A223069 Number of n X 2 0..3 arrays with successive rows and columns fitting to straight lines with nondecreasing slope, with a single point array taken as having zero slope.

Original entry on oeis.org

16, 150, 1080, 6627, 36552, 187000, 905440, 4206453, 18933408, 83153850, 358250280, 1520208679, 6373759384, 26468569500, 109080982800, 446806304505, 1821267503280, 7395000190750, 29933239010200, 120863093617131
Offset: 1

Views

Author

R. H. Hardin; Mar 14 2013

Keywords

Comments

Column 2 of A223071.

Examples

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

Formula

Empirical: a(n) = 16*a(n-1) -106*a(n-2) +376*a(n-3) -769*a(n-4) +904*a(n-5) -564*a(n-6) +144*a(n-7).
Empirical g.f.: x*(16 - 106*x + 376*x^2 - 769*x^3 + 904*x^4 - 564*x^5 + 144*x^6) / ((1 - x)^2*(1 - 2*x)^2*(1 - 3*x)^2*(1 - 4*x)). - Colin Barker, Feb 18 2018

A223070 Number of nX3 0..3 arrays with successive rows and columns fitting to straight lines with nondecreasing slope, with a single point array taken as having zero slope.

Original entry on oeis.org

64, 1080, 38512, 899390, 22520656, 462313688, 9567328752, 178464221290, 3336648010448, 58641450033936, 1033599371410096, 17499076161248060, 297470720803662048, 4917593684170711306, 81699455573347788176
Offset: 1

Views

Author

R. H. Hardin Mar 14 2013

Keywords

Comments

Column 3 of A223071

Examples

			Some solutions for n=3
..2..2..2....0..0..0....3..2..0....2..0..0....0..0..0....3..3..1....2..0..2
..1..0..2....1..0..2....0..2..1....1..1..3....1..2..3....1..0..1....1..2..2
..1..3..3....2..2..3....0..3..2....0..2..2....0..2..3....0..1..3....0..0..2
		
Showing 1-3 of 3 results.