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”).

A222124
Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..5 array extended with zeros and convolved with 1,2,1.
1
2, 3, 4, 8, 12, 19, 31, 48, 79, 126, 201, 323, 516, 827, 1324, 2120, 3396, 5436, 8706, 13940, 22323, 35748, 57240, 91661, 146778, 235035, 376367, 602677, 965074, 1545383, 2474634, 3962658, 6345442, 10161019, 16270937, 26054807, 41721820
OFFSET
1,1
COMMENTS
Column 5 of A222127.
LINKS
FORMULA
Empirical: a(n) = a(n-1) + a(n-3) + a(n-5) + a(n-8) + a(n-10) + 2*a(n-12) - a(n-13).
Empirical g.f.: x*(1 + x + x^2)*(2 - x + 3*x^3 - 2*x^4 + 3*x^6 - 2*x^7 + x^8 + 2*x^9 - x^10) / (1 - x - x^3 - x^5 - x^8 - x^10 - 2*x^12 + x^13). - Colin Barker, Aug 15 2018
EXAMPLE
Some solutions for n=7, one extended zero followed by filtered positions:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..0....1....0....1....1....1....1....0....0....0....0....0....0....0....0....0
..0....0....1....0....0....0....0....0....0....1....0....1....0....1....1....0
..0....0....0....0....1....0....0....0....0....0....1....0....0....0....0....0
..0....0....1....0....0....1....0....0....1....0....0....0....1....0....0....0
..0....1....0....0....0....0....0....0....0....0....0....0....0....1....1....1
..1....0....0....0....1....1....1....0....0....0....1....1....1....0....0....0
..0....0....1....1....0....0....0....1....0....0....0....0....0....0....1....1
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
CROSSREFS
Cf. A222127.
Sequence in context: A228718 A355958 A222123 * A222125 A222126 A004045
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 08 2013
STATUS
approved