This site is supported by donations to The OEIS Foundation.

 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!)
 A250437 Number of (n+1)X(2+1) 0..2 arrays with nondecreasing sum of every two consecutive values in every row and column 1
 324, 2160, 14400, 60000, 250000, 787500, 2480625, 6482700, 16941456, 38723328, 88510464, 182891520, 377913600, 721710000, 1378265625, 2470668750, 4428902500, 7537186800, 12826921536, 20901168288, 34057964304, 53488469580, 84004327225 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 2 of A250443 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 2*a(n-1) +10*a(n-2) -22*a(n-3) -44*a(n-4) +110*a(n-5) +110*a(n-6) -330*a(n-7) -165*a(n-8) +660*a(n-9) +132*a(n-10) -924*a(n-11) +924*a(n-13) -132*a(n-14) -660*a(n-15) +165*a(n-16) +330*a(n-17) -110*a(n-18) -110*a(n-19) +44*a(n-20) +22*a(n-21) -10*a(n-22) -2*a(n-23) +a(n-24) Empirical for n mod 2 = 0: a(n) = (1/2359296)*n^12 + (7/294912)*n^11 + (355/589824)*n^10 + (449/49152)*n^9 + (4541/49152)*n^8 + (1007/1536)*n^7 + (123317/36864)*n^6 + (113887/9216)*n^5 + (9439/288)*n^4 + (5837/96)*n^3 + (1197/16)*n^2 + (219/4)*n + 18 Empirical for n mod 2 = 1: a(n) = (1/2359296)*n^12 + (7/294912)*n^11 + (713/1179648)*n^10 + (2729/294912)*n^9 + (223799/2359296)*n^8 + (101131/147456)*n^7 + (2115031/589824)*n^6 + (2014145/147456)*n^5 + (88753375/2359296)*n^4 + (7180625/98304)*n^3 + (12440625/131072)*n^2 + (2428125/32768)*n + (6890625/262144) EXAMPLE Some solutions for n=4 ..0..2..0....0..0..1....0..0..0....0..1..0....0..1..0....1..0..2....0..1..0 ..0..1..2....0..1..0....1..0..2....0..1..1....0..2..0....0..1..1....0..0..2 ..0..2..2....1..2..1....0..1..1....1..1..2....0..1..1....1..1..2....0..1..1 ..2..2..2....2..1..2....1..1..2....2..2..2....1..2..2....0..2..2....1..0..2 ..0..2..2....1..2..2....1..2..1....1..1..2....1..1..1....2..1..2....1..1..2 CROSSREFS Sequence in context: A202486 A305070 A229538 * A064197 A233639 A203374 Adjacent sequences:  A250434 A250435 A250436 * A250438 A250439 A250440 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.

Last modified December 11 23:44 EST 2019. Contains 329945 sequences. (Running on oeis4.)