6660999

Appears in sequences

• 6*((10^n-1)/9)*(10^(n+1))+9*(10^n-1)/9.at n=3A246880
• a(n)=A246880(n) where no k exists such that A246880(n)=A002277(k)*(2*10^(A081677(k-1))+3).at n=1A246881