There is no built-in MATLAB function that performs the exact operation described.
However, you can use a single for-loop and the built-in "all" and "find" functions to create a custom function that will output the desired behavior:
>> function output = pattern(B, A)
>> SIZE = length(B) - length(A);
>> match = zeros(1, SIZE);
>> for i=1:SIZE
>> match(i) = all(B(i:i-1+length(A)) == A);
>> end
>> output = find(match == 1);
>> end
