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a(n) = floor(a(n-1)^(5/2)), a(1) = 2.
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%I #7 Apr 18 2022 12:01:54

%S 2,5,55,22434,75381849525,1560152215306022835807766096,

%T 96142947030750035305397690793504947854390697291777107758182668001398

%N a(n) = floor(a(n-1)^(5/2)), a(1) = 2.

%C The next term -- a(8) -- has 170 digits. - _Harvey P. Dale_, Apr 18 2022

%F a(n) ~ c^((5/2)^n), where c = 1.292359119971021796628915278748164958162881226395259818195999161... .

%t RecurrenceTable[{a[1]==2,a[n]==Floor[a[n-1]^(5/2)]},a,{n,1,10}]

%t NestList[Floor[(Sqrt[#])^5]&,2,10] (* _Harvey P. Dale_, Apr 18 2022 *)

%Y Cf. A254405.

%K nonn,easy

%O 1,1

%A _Vaclav Kotesovec_, Jan 30 2015