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

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A221964 Number of -5..5 arrays of length n with the sum ahead of each element differing from the sum following that element by 5 or less. 1
11, 121, 671, 4961, 34111, 241153, 1690623, 11888129, 83512319, 586864641, 4123582463, 28975366145, 203599740927, 1430630760449, 10052572086271, 70636158713857, 496337248845823, 3487600190423041, 24506230080798719 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 5 of A221967.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..79

FORMULA

Empirical: a(n) = 5*a(n-1) + 18*a(n-2) - 20*a(n-3) - 48*a(n-4) + 16*a(n-5) + 32*a(n-6).

Empirical g.f.: 11*x*(1 + 6*x - 12*x^2 - 32*x^3 + 16*x^4 + 32*x^5) / ((1 + x)*(1 - 6*x - 12*x^2 + 32*x^3 + 16*x^4 - 32*x^5)). - Colin Barker, Aug 11 2018

EXAMPLE

Some solutions for n=6:

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

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

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

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

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

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

CROSSREFS

Cf. A221967.

Sequence in context: A216131 A223392 A262468 * A223640 A223633 A223616

Adjacent sequences:  A221961 A221962 A221963 * A221965 A221966 A221967

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 01 2013

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 December 11 12:33 EST 2019. Contains 329916 sequences. (Running on oeis4.)