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A226845 Number of n X 1 (0,1,2) arrays of permanents of 2 X 2 subblocks of some (n+1) X 2 binary array. 1
3, 9, 23, 57, 145, 373, 957, 2449, 6267, 16045, 41083, 105185, 269297, 689465, 1765209, 4519393, 11570803, 29624209, 75845551, 194184025, 497160801, 1272858861, 3258844373, 8343475473, 21361432171, 54690732373, 140022269235 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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) + 2*a(n-3) + a(n-4) -a (n-5).

Empirical g.f.: x*(3 - x^2)*(1 + x^2) / (1 - 3*x + 2*x^2 - 2*x^3 - x^4 + x^5). - Colin Barker, Sep 06 2018

EXAMPLE

Some solutions for n=3:

..0....2....0....1....2....1....1....2....0....2....0....0....2....1....2....0

..0....1....1....2....2....1....2....1....0....2....2....1....0....1....2....2

..2....1....0....1....1....0....2....0....0....2....2....1....0....2....0....1

CROSSREFS

Column 1 of A226852.

Sequence in context: A292329 A133654 A193695 * A096574 A045650 A191342

Adjacent sequences:  A226842 A226843 A226844 * A226846 A226847 A226848

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 19 2013

STATUS

approved

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Last modified October 22 01:46 EDT 2020. Contains 337948 sequences. (Running on oeis4.)