I checked the man page here at work for top(1). Try using the -f flag. For example, top -f proc.log will save the first 16 processes to the file proc.log. top -n 37 -f proc-long.log will save the first 37 processes to a file called proc-long.log. For more information, please check out man 1 top on your system.

[Note: The flags and arguments are not always portable between systems. Please check the top manpage on your flavor before using]