1100110011001

1100110011001 is a binary numeral consisting of thirteen bits. It is often cited as a simple example of a recurring bit pattern in digital representation and testing contexts.

In decimal form, the value is 6553. In hexadecimal notation, it is 0x1999. This corresponds to the binary sequence when grouped into nibbles: 0001 1001 1001 1001 (upon padding to 16 bits), which highlights a repeating nibble pattern of 1 and 9 in hexadecimal.

The sequence itself shows a clear motif: two consecutive 1s followed by two consecutive 0s, repeated three times, with a trailing 1. Specifically, the pattern can be read as 11 00 11 00 11 00 1. The overall length and repetition make it a convenient test case for bitwise operations, shifting, masking, and pattern recognition in software and hardware design.

Because it maps neatly to a small set of hexadecimal digits, 0x1999, the string is sometimes used in demonstrations of binary-to-hexadecimal conversion and in exercises exploring endianess, word alignment, and binary arithmetic. While it has no intrinsic semantic meaning beyond its bit pattern, 1100110011001 serves as a concise, nontrivial example for illustrating core concepts in digital representations and numeral systems.