2430481

Appears in sequences

• G.f.: (108*x^2+27*x+1)/(1+2*x-6*x^2-27*x^3).at n=12A103645
• Numbers k that require four iterations of the sigma function to be >= 2*k.at n=26A107914
• Perfect squares which can be written neither as a^2+b^2, nor as a^2+2*b^2, nor as a^2+3*b^2, nor as a^2+7*b^2, with a > 0 and b > 0.at n=17A216408