a(n) = 10*a(n-1) + A109242(n).A180153a(n) = 10*a(n-1) + A109242(n).Terms a(0) =1a(1) =121a(2) =12421a(3) =1246421a(4) =124696421a(5) =12470296421External referencesoeis: A180153