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A276266 a(0) = a(1) = a(2) = 1; for n>2, a(n) = ( a(n-1)*a(n-2) + 1 )^2 / a(n-3). 2

%I #17 Aug 27 2016 02:23:58

%S 1,1,1,4,25,10201,16259565169,1100432328310492581042546436,

%T 31383529740086705883339675381564403354342372463018335778292540655564225

%N a(0) = a(1) = a(2) = 1; for n>2, a(n) = ( a(n-1)*a(n-2) + 1 )^2 / a(n-3).

%H Seiichi Manyama, <a href="/A276266/b276266.txt">Table of n, a(n) for n = 0..10</a>

%F a(n) = A208209(n)^2.

%t RecurrenceTable[{a[n] == (a[n - 1] a[n - 2] + 1)^2/a[n - 3], a[0] == a[1] == a[2] == 1}, a, {n, 0, 8}] (* _Michael De Vlieger_, Aug 26 2016 *)

%o (Ruby)

%o def A(m, n)

%o a = Array.new(m, 1)

%o ary = [1]

%o while ary.size < n + 1

%o i = a[1..-1].inject(:*) + 1

%o i *= i

%o break if i % a[0] > 0

%o a = *a[1..-1], i / a[0]

%o ary << a[0]

%o end

%o ary

%o end

%o def A276266(n)

%o A(3, n)

%o end

%Y Cf. A081068, A208209.

%K nonn

%O 0,4

%A _Seiichi Manyama_, Aug 26 2016

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Last modified March 28 05:39 EDT 2024. Contains 371235 sequences. (Running on oeis4.)