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URL: https://oeis.org/A116797

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A116797

Number of permutations of length n which avoid the patterns 1432, 2134, 2314.

0

1, 2, 6, 21, 73, 241, 768, 2415, 7587, 23905, 75507, 238759, 755088, 2387570, 7548085, 23860518, 75425046, 238427267, 753705647, 2382596754, 7531821990, 23809446690, 75265885442, 237928695207, 752134317626, 2377628496399

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..26.

D. Callan, T. Mansour, Enumeration of small Wilf classes avoiding 1324 and two other 4-letter patterns, arXiv:1705.00933 [math.CO] (2017), Table 2 No 98.

Lara Pudwell, Systematic Studies in Pattern Avoidance, 2005.

Index entries for linear recurrences with constant coefficients, signature (6,-13,15,-9,7,-4)

FORMULA

G.f.: A(x) = -{(3x^5-4x^4+4x^3-7x^2+4x-1)x}/{4x^6-7x^5+9x^4-15x^3+13x^2-6x+1}

CROSSREFS

Sequence in context: A116741 A116843 A116822 * A294804 A116744 A165521

Adjacent sequences: A116794 A116795 A116796 * A116798 A116799 A116800

KEYWORD

nonn,easy

AUTHOR

Lara Pudwell, Feb 26 2006

STATUS

approved