a(n)^2 is a triangular number: a(n) = 6*a(n-1) - a(n-2) with a(0)=0, a(1)=1.

A001109

a(n)^2 is a triangular number: a(n) = 6*a(n-1) - a(n-2) with a(0)=0, a(1)=1.

Terms

    a(0) =0a(1) =1a(2) =6a(3) =35a(4) =204a(5) =1189a(6) =6930a(7) =40391a(8) =235416a(9) =1372105a(10) =7997214a(11) =46611179a(12) =271669860a(13) =1583407981a(14) =9228778026a(15) =53789260175a(16) =313506783024

External references