Woodall number - Wikipedia, the free encyclopedia »

In mathematics, a Woodall number is a natural number of the form n · 2^n − 1 (written Wn). Woodall numbers were first studied by Allan J. C. Cunningham and H. J. Woodall in 1917, inspired by James Cullen’s earlier study of the similarly-defined Cullen numbers. The first few Woodall numbers are 1, 7, 23, 63, 159, 383, 895, … (sequence A003261 in OEIS). Woodall numbers curiously arise in Goodstein’s theorem.