

A250313


Number of length n+2 0..1 arrays with the sum of second differences squared multiplied by some arrangement of +1 equal to zero.


1



2, 8, 8, 24, 42, 104, 212, 464, 950, 1968, 3984, 8072, 16226, 32600, 65324, 130848, 261870, 524000, 1048232, 2096792, 4193882, 8388168, 16776708, 33553904, 67108262, 134217104, 268434752, 536870184, 1073741010, 2147482808, 4294966364
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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)  6*a(n3) + 3*a(n4) + 3*a(n5)  2*a(n6).
Empirical g.f.: 2*x*(1 + x  8*x^2 + 6*x^3 + 6*x^4  2*x^5) / ((1  x)^3*(1 + x)^2*(1  2*x)).  Colin Barker, Nov 12 2018


EXAMPLE

Some solutions for n=6:
..1....0....0....0....1....0....0....1....1....0....1....0....0....1....1....0
..1....0....0....1....1....0....1....1....0....0....0....1....1....0....0....0
..0....0....0....0....1....1....0....0....1....0....0....0....0....1....1....1
..0....0....1....0....0....1....1....1....0....1....1....1....0....1....1....1
..1....1....1....0....0....1....0....0....1....1....0....1....1....0....0....1
..0....0....1....0....1....1....0....0....0....1....0....1....1....0....0....0
..0....1....0....1....1....1....1....1....1....1....0....1....0....1....0....1
..0....1....0....0....1....1....0....1....0....1....1....0....1....0....1....1


CROSSREFS

Column 1 of A250320.
Sequence in context: A093907 A116471 A146749 * A180825 A230708 A230739
Adjacent sequences: A250310 A250311 A250312 * A250314 A250315 A250316


KEYWORD

nonn


AUTHOR

R. H. Hardin, Nov 18 2014


STATUS

approved



