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 1-2 of 2 results.

A250691 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 absolute value of x(i,j)-x(i-1,j) in the j direction.

Original entry on oeis.org

104, 543, 520, 2541, 2920, 2512, 11150, 13906, 15246, 11736, 47002, 60508, 74631, 76320, 53032, 193117, 249512, 324648, 383440, 362241, 233300, 780551, 995624, 1315446, 1670016, 1848953, 1647460, 1005121, 3122604, 3894542, 5098590, 6671458
Offset: 1

Views

Author

R. H. Hardin, Nov 26 2014

Keywords

Comments

Table starts
......104.......543.......2541.......11150.......47002......193117......780551
......520......2920......13906.......60508......249512......995624.....3894542
.....2512.....15246......74631......324648.....1315446.....5098590....19218493
....11736.....76320.....383440.....1670016.....6671458....25235016....92169818
....53032....362241....1848953.....8038566....31728758...117793753...420283865
...233300...1647460....8474002....36673634...143136866...523260542..1832718604
..1005121...7249825...37322413...160222342...617657415..2224688673..7662909389
..4260728..31113316..159438246...676640344..2571646112..9121206688.30911828018
.17835379.131014715..665575403..2784280670.10412478449.36332194553
.73930174.543845812.2731006288.11235235268.41269021168

Examples

			Some solutions for n=3 k=4
..2..3..1..0..0....2..2..3..2..2....2..2..1..1..0....0..1..0..0..0
..2..3..2..1..1....0..0..1..0..0....2..2..2..2..3....0..1..0..0..1
..1..2..1..0..0....0..0..1..1..1....1..1..1..1..2....1..2..1..1..2
..0..1..2..1..3....0..0..1..1..2....0..0..0..0..3....1..2..1..1..2
		

Crossrefs

Column 1 is A250669.
Rows 1-7 are A250692, ..., A250698.

Formula

Empirical for column k:
k=1: [linear recurrence of order 7] for n>11
k=2: [order 13] for n>17
k=3: [same order 13] for n>17
k=4: [same order 13] for n>17
k=5: [same order 13] for n>17
k=6: [same order 13] for n>17
k=7: [same order 13] for n>17
Empirical for row n:
n=1: [linear recurrence of order 7, cf. A250692]
n=2: [order 10, cf. A250693]
n=3: [order 16, cf. A250694]
n=4: [same order 16, cf. A250695]
n=5: [same order 16, cf. A250696]
n=6: [same order 16, cf. A250697]
n=7: [same order 16, cf. A250698].

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

Views

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
Showing 1-2 of 2 results.