130356

Appears in sequences

• Number of corners, or planar partitions of n with only one row and one column.at n=27A006330
• Numbers n such that the arithmetic, geometric and harmonic means of phi(n) and sigma(n) are all integers.at n=35A065146
• Sum of next n integer interprimes (cf. A024675).at n=32A075673
• Numbers k such that sigma(k) = 9*phi(k).at n=18A163667
• Numbers whose sum of their anti-divisors divides the sum of their divisors.at n=18A191581
• Numbers whose sum of anti-divisors is equal to the sum of its unitary divisors.at n=20A273992
• a(n) = Sum_{d|n} d*binomial(d+2,3).at n=28A321598
• Number of tilings of an equilateral triangle of side length n with unit triangles (of side length 1) and exactly two unit "lozenges" or "diamonds" (also of side length 1).at n=18A326367