The OEIS is supported by the many generous donors to the OEIS Foundation.

 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 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A223963 Number of 3 X n 0..3 arrays with antidiagonals unimodal and rows and diagonals nondecreasing. 1
 64, 707, 3471, 12311, 36028, 92734, 217144, 471994, 965172, 1874532, 3482781, 6225291, 10754192, 18022648, 29393806, 46779538, 72814768, 111073890, 166336539, 244910775, 355022580, 507281450, 715232788, 996008770, 1371090364 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row 3 of A223961. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = (1/8640)*n^9 + (1/320)*n^8 + (503/10080)*n^7 + (659/1440)*n^6 + (3013/960)*n^5 + (37141/2880)*n^4 + (106019/2160)*n^3 - (18977/720)*n^2 + (2711/70)*n - 6 for n>2. Conjectures from Colin Barker, Aug 24 2018: (Start) G.f.: x*(64 + 67*x - 719*x^2 + 1736*x^3 - 2287*x^4 + 2271*x^5 - 2070*x^6 + 1632*x^7 - 910*x^8 + 311*x^9 - 58*x^10 + 5*x^11) / (1 - x)^10. a(n) = 10*a(n-1) - 45*a(n-2) + 120*a(n-3) - 210*a(n-4) + 252*a(n-5) - 210*a(n-6) + 120*a(n-7) - 45*a(n-8) + 10*a(n-9) - a(n-10) for n>12. (End) EXAMPLE Some solutions for n=3: ..0..0..1....2..2..2....0..0..2....0..0..2....0..2..3....0..1..3....1..2..2 ..1..1..1....1..2..2....0..2..3....1..1..1....0..1..3....1..2..3....0..1..3 ..0..1..3....1..1..3....3..3..3....1..1..2....0..0..2....1..1..3....0..0..2 CROSSREFS Cf. A223961. Sequence in context: A119287 A318023 A320408 * A303726 A305229 A304774 Adjacent sequences: A223960 A223961 A223962 * A223964 A223965 A223966 KEYWORD nonn AUTHOR R. H. Hardin, Mar 29 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified November 27 22:56 EST 2022. Contains 358406 sequences. (Running on oeis4.)