a(n) is the difference between multiples of 5 with even and odd digit sum in base 4 in interval [0,4^n).

A212500

a(n) is the difference between multiples of 5 with even and odd digit sum in base 4 in interval [0,4^n).

Terms

    a(0) =1a(1) =4a(2) =7a(3) =36a(4) =65a(5) =340a(6) =615a(7) =3220a(8) =5825a(9) =30500a(10) =55175a(11) =288900a(12) =522625a(13) =2736500a(14) =4950375a(15) =25920500a(16) =46890625a(17) =245522500a(18) =444154375a(19) =2325622500a(20) =4207090625a(21) =22028612500a(22) =39850134375a(23) =208658012500a(24) =377465890625

External references