login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A202125 Number of -n..n arrays of 4 elements with first, second and third differences also in -n..n 2
19, 127, 475, 1279, 2833, 5509, 9739, 16039, 25003, 37279, 53605, 74797, 101719, 135331, 176671, 226819, 286957, 358345, 442279, 540163, 653479, 783739, 932569, 1101673, 1292779, 1507735, 1748467, 2016919, 2315161, 2645341, 3009619, 3410287 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A202124

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) -3*a(n-2) +3*a(n-3) -6*a(n-4) +6*a(n-5) -3*a(n-6) +3*a(n-7) -3*a(n-8) +a(n-9)

EXAMPLE

Some solutions for n=5

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

.-4...-4...-4...-1...-2....0....2....0...-4....2....2...-1...-1....0...-1....4

.-1...-5...-4...-2....0...-1....0....4...-2....2....0....0...-3...-2...-1....4

..1...-5....1....1....1....0....0....5....1....4...-4....1....0...-5....4....1

CROSSREFS

Sequence in context: A164905 A142106 A078851 * A169727 A177459 A142649

Adjacent sequences:  A202122 A202123 A202124 * A202126 A202127 A202128

KEYWORD

nonn

AUTHOR

R. H. Hardin Dec 11 2011

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 23 17:10 EST 2018. Contains 299584 sequences. (Running on oeis4.)