Answer is: >! 32 Search google for the remaining numbers in the sequence: >! https://goo.gl/oTOCNA Which gives >! The labels of [Interstate higways][1]. With both sequences one gets 1,2,3,4,5,6,7,8... Image added: >! [![enter image description here][2]][2] [1]: https://en.wikipedia.org/wiki/Interstate_Highway_System [2]: https://i.sstatic.net/KKfUI.png