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!)
 A250653 Number of (n+1)X(5+1) 0..1 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction 2
 49, 103, 211, 427, 859, 1723, 3451, 6907, 13819, 27643, 55291, 110587, 221179, 442363, 884731, 1769467, 3538939, 7077883, 14155771, 28311547, 56623099, 113246203, 226492411, 452984827, 905969659, 1811939323, 3623878651 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 5 of A250656. Since one edge length of the array is fixed, and the constraint is a Markov-type correlation between fixed-width lengths of the other edge, the generating function is computable by the usual transfer matrix method and therefore a rational polynomial. That predicts that there is a linear recurrence. - R. J. Mathar, May 25 2018 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 3*a(n-1) - 2*a(n-2); also a(n) = 2^(n-1)*25 + (5*2^(n-1)-1)*5 + 2^(n+1). It appears that a(n) = 27*2^n-5, which would make this coincide with A304387. - N. J. A. Sloane, May 13 2018 EXAMPLE Some solutions for n=4 ..1..1..1..0..0..0....1..1..1..1..1..1....1..1..1..1..1..1....1..1..1..1..0..0 ..0..0..0..0..0..0....1..1..1..1..1..1....1..1..1..1..1..1....0..0..0..0..0..0 ..1..1..1..1..1..1....0..0..0..0..0..0....0..0..0..0..0..0....1..1..1..1..1..1 ..1..1..1..1..1..1....0..0..0..0..0..0....0..0..0..0..0..0....1..1..1..1..1..1 ..0..0..0..0..1..1....1..1..1..1..1..1....0..0..0..0..1..1....0..0..0..1..1..1 CROSSREFS Cf. A304387. Sequence in context: A019547 A228878 A067673 * A045253 A088868 A044236 Adjacent sequences: A250650 A250651 A250652 * A250654 A250655 A250656 KEYWORD nonn AUTHOR R. H. Hardin, Nov 26 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 3 20:26 EST 2022. Contains 358543 sequences. (Running on oeis4.)