The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons 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 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A223580 Number of nX3 0..3 arrays with antidiagonals unimodal 1
 64, 4096, 204800, 10240000, 512000000, 25600000000, 1280000000000, 64000000000000, 3200000000000000, 160000000000000000, 8000000000000000000, 400000000000000000000, 20000000000000000000000, 1000000000000000000000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 3 of A223585 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Let U(z) = (z^6+15*z^5+115*z^4+405*z^3+964*z^2+660*z+720)/720 a(n) = U(min(n,3))^(max(n,3)-min(n,3)+1) * product{ U(i)^2 , i=1..(min(n,3)-1) } a(n) = 50*a(n-1) for n>2 EXAMPLE Some solutions for n=3 ..2..2..1....2..0..3....2..3..0....0..2..1....2..2..0....0..1..0....0..3..0 ..3..1..3....3..3..3....0..1..1....0..1..1....1..3..1....1..3..0....2..1..0 ..2..0..2....1..1..0....3..1..2....1..3..0....2..3..0....3..2..1....0..3..2 CROSSREFS Sequence in context: A297379 A283862 A223567 * A267971 A229102 A222934 Adjacent sequences:  A223577 A223578 A223579 * A223581 A223582 A223583 KEYWORD nonn AUTHOR R. H. Hardin Mar 22 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.

Last modified December 3 22:32 EST 2021. Contains 349468 sequences. (Running on oeis4.)