99101

Appears in sequences

• Numbers x such that sigma(x)-x divides x-1, other than prime powers.at n=22A059047
• Smallest composite number in base n which contains its largest proper factor as a substring.at n=38A063248
• Triangle read by rows: T(n,k) (0 <= k <= ceiling(n/2)-2) is the number of (1,1) steps starting at level k in all peakless Motzkin paths of length n (can be easily translated into RNA secondary structure terminology).at n=50A110238
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (-1, 1, -1), (0, 0, 1), (1, 0, 0)}.at n=10A149916
• Composite numbers which contain their sum of aliquot parts as a substring.at n=23A225417
• a(n) = 991*n^2 + 1.at n=10A237991
• Numbers n such that there are a, b with abs(sigma(a) - sigma(b)) = sigma(n) - n and a U b = n, where U is decimal concatenation.at n=29A239563
• Numbers x such that x = concatenate(a, b) and phi(a) + phi(b) = sigma(x) - x.at n=15A254624