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!)
A204216 Number of length 8 nonnegative integer arrays starting and ending with 0 with adjacent elements differing by no more than n. 1
127, 1925, 12492, 51945, 164255, 431445, 991152, 2057553, 3945655, 7098949, 12120428, 19806969, 31187079, 47562005, 70550208, 102135201, 144716751, 201165445, 274880620, 369851657, 490722639, 642860373, 832425776, 1066448625 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A204213.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = (841/180)*n^6 + (101/5)*n^5 + (1325/36)*n^4 + (73/2)*n^3 + (946/45)*n^2 + (34/5)*n + 1.

Conjectures from Colin Barker, Jun 06 2018: (Start)

G.f.: x*(127 + 1036*x + 1684*x^2 + 481*x^3 + 42*x^4 - 7*x^5 + x^6) / (1 - x)^7.

a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>7.

(End)

EXAMPLE

Some solutions for n=4:

..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

..2....3....3....2....3....2....3....4....1....4....4....4....1....4....3....3

..3....5....0....2....2....0....6....0....1....4....8....8....1....6....5....2

..4....4....1....5....5....2....8....2....1....5....5....4....0....9....7....3

..4....5....3....7....6....3....6....6....4....2....3....2....1....6...10....1

..7....4....6....7....6....2....2....3....3....0....6....1....3....2....6....2

..4....2....4....4....3....0....2....4....2....1....4....0....4....1....3....1

..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

CROSSREFS

Cf. A204213.

Sequence in context: A025598 A115153 A172408 * A075937 A075938 A258003

Adjacent sequences:  A204213 A204214 A204215 * A204217 A204218 A204219

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 12 2012

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 18 10:05 EDT 2022. Contains 353792 sequences. (Running on oeis4.)