0,2

After the first term, all terms seem to be a multiple of 3.

a(n) = sqrt(A083353(n))

A083352(x)=1 + 3x + 9x^2 + 9x^3 + 3x^4 + 15x^5 + 33x^6 +...; so that

A083353(x) = A083352(x)^2 + A083352(x) - 1 = 1 + 9x + 36x^2 + 81x^3 + 144x^4 + 225x^5 +...

Cf. A083352, A083353.

Sequence in context: A028251 A039004 A070021 this_sequence A156242 A060293 A123581

Adjacent sequences: A083351 A083352 A083353 this_sequence A083355 A083356 A083357

nonn

Paul D. Hanna (pauldhanna(AT)juno.com), Apr 26 2003