This Bible contradiction is from the Skeptic's Annotated Bible.
2 Samuel 3:2-5
2 Samuel 3:2-5 View context
And unto David were sons born in Hebron: and his firstborn was Amnon, of Ahinoam the Jezreelitess;
And his second, Chileab, of Abigail the wife of Nabal the Carmelite; and the third, Absalom the son of Maacah the daughter of Talmai king of Geshur;
And the fourth, Adonijah the son of Haggith; and the fifth, Shephatiah the son of Abital;
And the sixth, Ithream, by Eglah David's wife. These were born to David in Hebron.
1 Chronicles 3
1 Chronicles 3:1-4 View context
Now these were the sons of David, which were born unto him in Hebron; the firstborn Amnon, of Ahinoam the Jezreelitess; the second Daniel, of Abigail the Carmelitess:
The third, Absalom the son of Maachah the daughter of Talmai king of Geshur: the fourth, Adonijah the son of Haggith:
The fifth, Shephatiah of Abital: the sixth, Ithream by Eglah his wife.
[These] six were born unto him in Hebron; and there he reigned seven years and six months: and in Jerusalem he reigned thirty and three years.