A palindromic sequence is defined as the a sequence on double stranded DNA/RNA which is the same when read from 5′ to 3′ on one strand and 5′ to 3′ on the other or complementary strand.
Example of complementary strand:
If one strand has the sequence 5′ ATTGCCC 3′ then the complementary strand means other strand of double strand would have the sequence 3′ TAACGGG 5′
Example of palindromic strand:
If one strand has the sequence 5′ ATTGCCC 3′ then its palindromic sequence will be 3′-CCCGTTA-5′
Therefore, palindromic sequence is defined as same sequence when either reads from backward or forward. When we read “madam” then it is same when reads from backward or forward.