login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A270850 T(n,k)=Number of nXnXn triangular 0..k arrays with some element plus some adjacent element totalling k+1, k or k-1 exactly once. 12
0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 24, 30, 0, 0, 0, 66, 270, 252, 0, 0, 0, 120, 1650, 6822, 2298, 0, 0, 0, 198, 7344, 108348, 307494, 28440, 0, 0, 0, 288, 24954, 1144464, 15754872, 27582438, 460494, 0, 0, 0, 402, 68838, 8559378, 469037376, 5805948474, 4875050400 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,8

COMMENTS

Table starts

.0.0......0..........0.............0................0..................0

.0.0......6.........24............66..............120................198

.0.0.....30........270..........1650.............7344..............24954

.0.0....252.......6822........108348..........1144464............8559378

.0.0...2298.....307494......15754872........469037376.........8746813158

.0.0..28440...27582438....5805948474.....571228600932.....29999932959600

.0.0.460494.4875050400.5281372355106.2104222937252028.358240737864481086

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..127

FORMULA

Empirical for row n:

n=1: a(n) = a(n-1)

n=2: a(n) = 2*a(n-1) -2*a(n-3) +a(n-4) for n>5

n=3: [order 10] for n>17

n=4: [order 18] for n>33

Empirical quasipolynomials for row n:

n=2: polynomial of degree 2 plus a quasipolynomial of degree 0 with period 2 for n>1

n=3: polynomial of degree 5 plus a quasipolynomial of degree 3 with period 2 for n>7

n=4: polynomial of degree 9 plus a quasipolynomial of degree 7 with period 2 for n>15

EXAMPLE

Some solutions for n=4 k=4

.....3........0........4........3........2........3........0........0

....4.3......0.1......4.4......4.4......4.4......4.4......0.0......1.2

...4.2.4....1.0.1....2.4.3....3.3.3....3.4.4....2.4.4....0.0.0....1.0.0

..3.4.4.3..2.0.1.0..4.2.4.3..2.4.4.3..4.2.4.2..0.4.4.2..2.1.0.2..0.1.1.1

CROSSREFS

Sequence in context: A308091 A096527 A028599 * A305324 A322379 A225339

Adjacent sequences:  A270847 A270848 A270849 * A270851 A270852 A270853

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Mar 24 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 22 23:50 EST 2022. Contains 350504 sequences. (Running on oeis4.)