Starting position of the first occurrence of a string of 2^n in the decimal expansion of Pi.

Terms

a(0) =1a(1) =6a(2) =2a(3) =11a(4) =40a(5) =15a(6) =22a(7) =148a(8) =1750a(9) =1842a(10) =12735a(11) =26862a(12) =27372a(13) =2943a(14) =37619a(15) =39587a(16) =106920a(17) =820238a(18) =76875a(19) =47887a(20) =6150809a(21) =3660438a(22) =17376657a(23) =15416321a(24) =162454456a(25) =132295965a(26) =265234498a(27) =33844308a(28) =4847933000a(29) =671531549