1010101

1010101 is a binary string of seven digits that alternates between 1 and 0, beginning and ending with 1. In binary notation, it represents the decimal value 85. The sequence is palindromic, reading the same forwards and backwards, and consists of runs of single bits rather than longer blocks.

As an 8-bit pattern, padding a leading zero yields 01010101, which corresponds to the hexadecimal value 0x55 and the decimal value 85. In ASCII, 0x55 denotes the uppercase letter U.

In computing and digital hardware, 1010101 is often cited as a simple test pattern because it rapidly toggles bit states, helping to verify data integrity on buses or to exercise combinational logic and routing without long runs of identical bits.

It can also appear in discussions of binary numerals, pattern generation, and introductory examples of bitwise arithmetic.