n is equal to the number of 4s in all numbers <= n written in base 7.

A014888

n is equal to the number of 4s in all numbers <= n written in base 7.

Terms

    a(0) =761729a(1) =761730a(2) =823543a(3) =1585272a(4) =1585273a(5) =1647086a(6) =2408815a(7) =2408816a(8) =2470629a(9) =3232358a(10) =3232359

External references