4^(2^n) + 3^(2^n) + 2^(2^n) + 1.A2472074^(2^n) + 3^(2^n) + 2^(2^n) + 1.Terms a(0) =10a(1) =30a(2) =354a(3) =72354a(4) =4338079554External referencesoeis: A247207