login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A250428
Number of (n+1)X(4+1) 0..1 arrays with nondecreasing sum of every two consecutive values in every row and column
1
144, 720, 3600, 12000, 40000, 105000, 275625, 617400, 1382976, 2765952, 5531904, 10160640, 18662400, 32076000, 55130625, 89842500, 146410000, 228399600, 356303376, 535927392, 806105664, 1175570760, 1714374025, 2434614000
OFFSET
1,1
COMMENTS
Column 4 of A250432
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +8*a(n-2) -18*a(n-3) -27*a(n-4) +72*a(n-5) +48*a(n-6) -168*a(n-7) -42*a(n-8) +252*a(n-9) -252*a(n-11) +42*a(n-12) +168*a(n-13) -48*a(n-14) -72*a(n-15) +27*a(n-16) +18*a(n-17) -8*a(n-18) -2*a(n-19) +a(n-20)
Empirical for n mod 2 = 0: a(n) = (1/147456)*n^10 + (23/73728)*n^9 + (13/2048)*n^8 + (77/1024)*n^7 + (1763/3072)*n^6 + (4525/1536)*n^5 + (5927/576)*n^4 + (3473/144)*n^3 + (145/4)*n^2 + (63/2)*n + 12
Empirical for n mod 2 = 1: a(n) = (1/147456)*n^10 + (23/73728)*n^9 + (941/147456)*n^8 + (1409/18432)*n^7 + (43777/73728)*n^6 + (115189/36864)*n^5 + (831857/73728)*n^4 + (169595/6144)*n^3 + (717525/16384)*n^2 + (333375/8192)*n + (275625/16384).
a(n+1)=A202095(n). - R. J. Mathar, Dec 04 2014
EXAMPLE
Some solutions for n=6
..0..0..0..1..0....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0
..0..0..0..0..1....0..0..0..1..0....0..1..0..1..1....0..0..0..1..1
..0..0..1..1..1....0..0..0..1..0....0..0..0..0..0....0..0..1..0..1
..0..1..0..1..1....0..0..0..1..1....1..1..1..1..1....0..1..0..1..1
..1..0..1..1..1....0..1..0..1..1....0..0..1..0..1....1..0..1..0..1
..1..1..1..1..1....0..0..0..1..1....1..1..1..1..1....0..1..1..1..1
..1..1..1..1..1....0..1..0..1..1....0..0..1..1..1....1..0..1..1..1
CROSSREFS
Sequence in context: A204391 A233903 A233897 * A033696 A233653 A233646
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 22 2014
STATUS
approved