

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
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OFFSET

1,1


LINKS

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


FORMULA

Empirical: a(n) = 3*a(n1)  2*a(n2) + 2*a(n3) + a(n4) a (n5).
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



