As character names:

U+2211 N-ARY SUMMATION character (∑)

As raw characters:

∑

As a string of HTML entities:

∑

Decoder output:

Byte number 1 is decimal 226, hex 0xE2, octal \342, binary 11100010
This is the first byte of a 3 byte sequence.

Byte number 2 is decimal 136, hex 0x88, octal \210, binary 10001000
This is continuation byte 1, expecting 1 more.

Byte number 3 is decimal 145, hex 0x91, octal \221, binary 10010001
This is continuation byte 2, expecting 0 more.

U+2211	N-ARY SUMMATION
	= summation sign
	x (greek capital letter sigma - 03A3)
	x (double-struck n-ary summation - 2140)