oeis.orgA077499 - OEIS 2, 3, 5, 17, 23, 89, 257, 353, 1409, 2663, 30977, 65537, 170369, 495617, 5767169, 23068673, 59969537, 82458113, 453519617, 3429742097, 4715895383, 15352201217, 39909726209, 1857616347137, 45732811767809, 96757023244289 (list; graph; refs; listen; history; text; internal format)