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A121883 a(n) = (2*a(n - 1)a(n - 3) + a(n - 2)^2)/a(n - 4) 0
1, 1, 1, 1, 3, 7, 23, 187, 1049, 11889, 241169, 3461609, 133910987, 6440667383, 259246821927, 32041224742643, 3584042412456241, 447926142061771361, 160270294066699831201, 42116645114696072883921 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

REFERENCES

A. N. W. Hone, Algebraic curves, integer sequences and a discrete Painleve transcendent, Proceedings of SIDE 6, Helsinki, Finland, 2004.

LINKS

Table of n, a(n) for n=1..20.

MATHEMATICA

a[n_] := a[n] = (2*a[n - 1]a[n - 3] + a[n - 2]^2)/a[n - 4]; a[0] = 1; a[1] = 1; a[2] = 1; a[3] = 1; Table[a[n], {n, 0, 30}]

RecurrenceTable[{a[1]==a[2]==a[3]==a[4]==1, a[n]==(2a[n-1]a[n-3]+ a[n-2]^2)/ a[n-4]}, a, {n, 20}] (* Harvey P. Dale, May 27 2014 *)

CROSSREFS

Cf. A006720, A014125, A095708.

Sequence in context: A145938 A048721 A113824 * A262264 A060235 A090188

Adjacent sequences:  A121880 A121881 A121882 * A121884 A121885 A121886

KEYWORD

nonn

AUTHOR

Roger L. Bagula, Sep 09 2006

EXTENSIONS

Edited by N. J. A. Sloane, Sep 15 2006

STATUS

approved

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Last modified August 20 20:50 EDT 2019. Contains 326155 sequences. (Running on oeis4.)