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!)
A250438 Number of (n+1)X(3+1) 0..2 arrays with nondecreasing sum of every two consecutive values in every row and column 1
1296, 14400, 160000, 1000000, 6250000, 27562500, 121550625, 423536400, 1475789056, 4337012736, 12745506816, 32920473600, 85030560000, 198470250000, 463250390625, 996503062500, 2143588810000, 4311270849600, 8670998958336 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A250443

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +14*a(n-2) -30*a(n-3) -90*a(n-4) +210*a(n-5) +350*a(n-6) -910*a(n-7) -910*a(n-8) +2730*a(n-9) +1638*a(n-10) -6006*a(n-11) -2002*a(n-12) +10010*a(n-13) +1430*a(n-14) -12870*a(n-15) +12870*a(n-17) -1430*a(n-18) -10010*a(n-19) +2002*a(n-20) +6006*a(n-21) -1638*a(n-22) -2730*a(n-23) +910*a(n-24) +910*a(n-25) -350*a(n-26) -210*a(n-27) +90*a(n-28) +30*a(n-29) -14*a(n-30) -2*a(n-31) +a(n-32)

Empirical for n mod 2 = 0: a(n) = (1/1358954496)*n^16 + (5/84934656)*n^15 + (31/14155776)*n^14 + (2135/42467328)*n^13 + (33847/42467328)*n^12 + (32735/3538944)*n^11 + (431429/5308416)*n^10 + (1463225/2654208)*n^9 + (5160755/1769472)*n^8 + (8008825/663552)*n^7 + (12913699/331776)*n^6 + (6965/72)*n^5 + (139417/768)*n^4 + (23855/96)*n^3 + (3741/16)*n^2 + 135*n + 36

Empirical for n mod 2 = 1: a(n) = (1/1358954496)*n^16 + (5/84934656)*n^15 + (373/169869312)*n^14 + (1435/28311552)*n^13 + (275299/339738624)*n^12 + (807985/84934656)*n^11 + (14409143/169869312)*n^10 + (49767325/84934656)*n^9 + (2153003003/679477248)*n^8 + (380990005/28311552)*n^7 + (7598369275/169869312)*n^6 + (9778683875/84934656)*n^5 + (76415846875/339738624)*n^4 + (9127365625/28311552)*n^3 + (2011296875/6291456)*n^2 + (616328125/3145728)*n + (937890625/16777216)

EXAMPLE

Some solutions for n=3

..0..1..0..1....0..0..1..1....0..0..0..2....0..0..1..0....0..0..0..1

..1..2..2..2....0..0..0..0....1..2..2..2....1..0..2..1....0..1..2..2

..0..1..0..1....0..1..2..2....2..2..2..2....0..2..2..2....1..0..2..2

..2..2..2..2....0..0..1..1....2..2..2..2....1..1..2..1....0..1..2..2

CROSSREFS

Sequence in context: A276282 A137488 A189991 * A221006 A016864 A064785

Adjacent sequences:  A250435 A250436 A250437 * A250439 A250440 A250441

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 22 2014

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 15 04:23 EST 2019. Contains 329991 sequences. (Running on oeis4.)