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A062257 Number of (0,1)-strings of length n with no occurrences of the substrings 10101101 and 1110101. 4
1, 2, 4, 8, 16, 32, 64, 127, 251, 496, 981, 1940, 3837, 7590, 15015, 29704, 58763, 116249, 229971, 454942, 899991, 1780410, 3522102, 6967611, 13783703, 27267665, 53942368, 106711708, 211102869, 417615105, 826148769, 1634332138 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

REFERENCES

I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, Wiley, N.Y., 1983, (Example 2.8.11).

LINKS

Table of n, a(n) for n=0..31.

FORMULA

G.f.: (1+x^5+x^6+x^7-x^9)/(1+x^5-x^6-x^9-2*x-x^8+x^10). a(n) = 2*a(n-1)-a(n-5)+a(n-6)+a(n-8)+a(n-9)-a(n-10).

CROSSREFS

Cf. A062258, A062259.

Sequence in context: A054044 A008859 A145113 * A208127 A172316 A062258

Adjacent sequences:  A062254 A062255 A062256 * A062258 A062259 A062260

KEYWORD

nonn

AUTHOR

Vladeta Jovovic, Jun 14 2001

STATUS

approved

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Last modified May 25 04:50 EDT 2019. Contains 323539 sequences. (Running on oeis4.)