A276256 A nonlinear recurrence of order 3: a(1)=a(2)=a(3)=1; a(n)=(a(n-1)+a(n-2)+1)^2/a(n-3).

1, 1, 1, 9, 121, 17161, 33189121, 9112869675009, 4839170130591864288001, 705579627764469400107962287271157001, 54630717750911142085059359537536676834981970103054482555001

Offset: 1

Author

Seiichi Manyama, Aug 25 2016

Keywords

• nonn

Comments

All terms are perfect squares.

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..16

Crossrefs

Cf. A276095.

Formula

a(n) = A276258(n)^2.

a(n) = 16*a(n-1)*a(n-2) - 2a(n-1) - 2a(n-2) - 2 - a(n-3).

a(n)*a(n-1)*a(n-2) = ((a(n) + a(n-1) + a(n-2) + 1)/4)^2.