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A145502 a(n+1)=a(n)^2+2*a(n)-2 and a(1)=2 9
2, 6, 46, 2206, 4870846, 23725150497406, 562882766124611619513723646, 316837008400094222150776738483768236006420971486980606 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

General formula for a(n+1)=a(n)^2+2*a(n)-2 and a(1)=k+1 is a(n)=Floor[((k + Sqrt[k^2 + 4])/2)^(2^((n+1) - 1))

MATHEMATICA

aa = {}; k = 2; Do[AppendTo[aa, k]; k = k^2 + 2 k - 2, {n, 1, 10}]; aa

or

k = 1; Table[Floor[((k + Sqrt[k^2 + 4])/2)^(2^(n - 1))], {n, 2, 7}] (*Artur Jasinski*)

CROSSREFS

A145502-A145511

Sequence in context: A078603 A001587 A078537 * A072444 A052596 A098710

Adjacent sequences:  A145499 A145500 A145501 * A145503 A145504 A145505

KEYWORD

nonn

AUTHOR

Artur Jasinski (grafix(AT)csl.pl), Oct 11 2008

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Last modified February 14 23:53 EST 2012. Contains 205689 sequences.