A015945 Positive integers n such that n | (2^n + n/2 + 1).

2, 10, 50, 250, 410, 1250, 2050, 5050, 6250, 10250, 16810, 25250, 31250, 51250, 84050, 126250, 156250, 207050, 256250, 336610, 405050, 420250, 510050, 631250, 689210, 781250, 1035250, 1281250, 1683050, 1750250, 2025250, 2101250, 2550250, 3156250, 3446050

Offset: 1

Author

Robert G. Wilson v

Keywords

• nonn

Programs

Python

A015945_list = [n for n in range(2,10**6,2) if pow(2,n,n) == n//2-1] # Chai Wah Wu, Mar 25 2021

Formula

a(n) = 2 * A015950(n). - Max Alekseyev, Aug 04 2011