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A164420
Number of binary strings of length n with no substrings equal to 0000, 0010, or 0111.
2
1, 2, 4, 8, 13, 21, 33, 52, 81, 125, 193, 297, 457, 702, 1078, 1655, 2540, 3898, 5981, 9177, 14080, 21602, 33142, 50846, 78007, 119676, 183603, 281677, 432138, 662969, 1017100, 1560393, 2393890, 3672606, 5634358, 8643995, 13261253, 20344855, 31212218, 47884467
OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..2000 (terms n=4..500 from R. H. Hardin)
FORMULA
G.f.: (x+1)*(x^3+x^2+1)/((x-1)*(x^5+x^4+x^3+x^2-1)). - R. J. Mathar, Dec 01 2011
MATHEMATICA
CoefficientList[Series[(x + 1) (x^3 + x^2 + 1)/((x - 1) (x^5 + x^4 + x^3 + x^2 - 1)), {x, 0, 39}], x] (* Michael De Vlieger, Oct 11 2017 *)
CROSSREFS
Sequence in context: A241691 A164429 A073336 * A164457 A164419 A164431
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Aug 14 2009
EXTENSIONS
Edited by Alois P. Heinz, Oct 09 2017
STATUS
approved