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A221992 Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..1 array extended with zeros and convolved with 1,4,6,4,1. 1
2, 3, 4, 6, 10, 15, 22, 35, 54, 81, 125, 193, 294, 450, 692, 1060, 1622, 2488, 3815, 5843, 8955, 13729, 21038, 32239, 49415, 75734, 116062, 177879, 272623, 417812, 640332, 981380, 1504053, 2305088, 3532772, 5414309, 8297912, 12717320, 19490493 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A221999.

LINKS

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

FORMULA

Empirical: a(n) = a(n-1) + 2*a(n-3) - a(n-4) - a(n-6) + a(n-7).

Empirical g.f.: x*(1 + x + x^2)*(2 - x - x^3 + x^4) / (1 - x - 2*x^3 + x^4 + x^6 - x^7). - Colin Barker, Aug 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

..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0

..0....0....0....0....1....0....0....1....0....0....0....1....1....0....0....1

..0....0....1....0....0....0....1....0....0....0....1....0....0....0....0....0

..1....0....0....1....0....0....0....0....1....0....0....0....0....0....0....0

..0....0....0....0....1....1....0....0....0....1....1....0....0....0....0....1

..1....0....0....0....0....0....0....0....0....0....0....1....0....1....0....0

..0....0....0....0....0....0....0....0....1....1....0....0....1....0....1....0

..0....1....1....0....0....1....0....0....0....0....0....0....0....0....0....1

..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

CROSSREFS

Cf. A221999.

Sequence in context: A147788 A104977 A206742 * A221993 A221994 A222021

Adjacent sequences:  A221989 A221990 A221991 * A221993 A221994 A221995

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 03 2013

STATUS

approved

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Last modified May 21 06:36 EDT 2022. Contains 353889 sequences. (Running on oeis4.)