347049

Appears in sequences

• Numbers n such that sigma(n) - n = sigma(n') - n', where n' is the arithmetic derivative of n.at n=12A239726
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1), where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences.at n=23A294541