A222122 Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..3 array extended with zeros and convolved with 1,2,1.

2, 3, 4, 7, 11, 17, 27, 42, 66, 104, 163, 256, 402, 631, 991, 1556, 2443, 3836, 6023, 9457, 14849, 23315, 36608, 57480, 90252, 141709, 222504, 349364, 548553, 861309, 1352382, 2123439, 3334112, 5235047, 8219795, 12906289, 20264775, 31818682

Offset

1,1

Comments

Column 3 of A222127.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) + a(n-3) + a(n-5).

Empirical g.f.: x*(2 + x + x^2 + x^3 + x^4) / (1 - x - x^3 - x^5). - Colin Barker, Mar 14 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
..1....1....0....0....0....0....0....0....0....0....0....0....0....0....0....1
..0....0....0....1....1....1....0....1....1....0....0....0....1....0....0....0
..0....0....0....0....0....0....0....0....0....0....1....0....0....0....0....0
..0....0....0....1....0....0....1....0....0....0....0....0....0....1....0....1
..0....1....1....0....0....0....0....1....1....1....0....0....0....0....0....0
..0....0....0....0....1....0....0....0....0....0....1....0....0....1....0....0
..1....1....0....1....0....1....0....1....0....1....0....1....0....0....0....1
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

Crossrefs

Cf. A222127.

Sequence in context: A165407 A039897 A297789 * A222024 A222025 A222026

Adjacent sequences: A222119 A222120 A222121 * A222123 A222124 A222125

Keyword

nonn

Author

R. H. Hardin, Feb 08 2013

Status

approved