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A143392 A quadratic recursion sequence: a(n)=a(n - 1)^2 - 2*a(n - 1) - a(n - 2)^2 + 2*a(n - 2). 0
1, 2, 1, -1, 4, 5, 7, 20, 325, 104615, 10943984020, 119770786197183303365, 14345041226291394498726932547331126324135, 205780207783999715270619814569860727079365052973702253248437750317796955577133 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..14.

FORMULA

a(n)=a(n - 1)^2 - 2*a(n - 1) - a(n - 2)^2 + 2*a(n - 2).

log a(n) ~ 0.011287... * 2^n - Charles R Greathouse IV, Oct 06 2009

MATHEMATICA

Clear[a, n]; a[0] = 1; a[1] = 2; a[n_] := a[n] = a[n - 1]^2 - 2*a[n - 1] - a[n - 2]^2 + 2*a[n - 2]; Table[a[n], {n, 0, 15}]

CROSSREFS

Sequence in context: A078047 A329689 A270952 * A090668 A307977 A295259

Adjacent sequences:  A143389 A143390 A143391 * A143393 A143394 A143395

KEYWORD

sign

AUTHOR

Roger L. Bagula and Gary W. Adamson, Oct 23 2008

STATUS

approved

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Last modified May 14 18:23 EDT 2021. Contains 343900 sequences. (Running on oeis4.)