

A207095


Number of 0..3 arrays x(0..n1) of n elements with each no smaller than the sum of its two previous neighbors modulo 4


1



4, 10, 26, 68, 176, 458, 1193, 3103, 8069, 20982, 54556, 141854, 368847, 959072, 2493770, 6484280, 16860367, 43840173, 113992823, 296403114, 770704718, 2003979505, 5210729566, 13548892363, 35229708616, 91603972925, 238187830252
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OFFSET

1,1


COMMENTS

Column 3 of A207100


LINKS

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


FORMULA

Empirical: a(n) = 3*a(n1) a(n2) +a(n3) 3*a(n4) +a(n6) 2*a(n9) +2*a(n12) +a(n13) a(n16)


EXAMPLE

Some solutions for n=5
..0....2....2....0....2....0....1....2....0....1....2....0....1....0....1....3
..2....3....2....0....3....1....1....3....1....2....2....2....1....0....2....3
..3....1....3....0....2....3....2....3....2....3....2....3....3....3....3....2
..2....3....1....1....3....2....3....3....3....2....3....2....2....3....2....3
..3....2....2....1....1....3....2....2....1....2....3....1....2....3....3....3


CROSSREFS

Sequence in context: A191605 A277236 A218208 * A126358 A200051 A200663
Adjacent sequences: A207092 A207093 A207094 * A207096 A207097 A207098


KEYWORD

nonn


AUTHOR

R. H. Hardin Feb 15 2012


STATUS

approved



