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1,1
Sequence with a(1) = 1 is decimal expansion of sqrt(5 - sqrt(5 - sqrt(5 - sqrt(5 - ... )))) - A222135.
Table of n, a(n) for n=1..101.
Closed form: (sqrt(21) + 1)/2 = A090458-1 = A107905-2 = A222135+1.
sqrt(5 + sqrt(5 + sqrt(5 + sqrt(5 + ... )))) - 1 = sqrt(5 - sqrt(5 - sqrt(5 - sqrt(5 - ... )))). See A222135.
2.791287847477920003294023596864...
RealDigits[(1 + Sqrt[21])/2, 10, 130]
Cf. A090458, A107905, A222135.
Sequence in context: A198322 A081999 A252661 * A011355 A240961 A198122
Adjacent sequences: A222131 A222132 A222133 * A222135 A222136 A222137
nonn,cons
Jaroslav Krizek, Feb 08 2013
approved