180432

Appears in sequences

• Numbers n such that 9*10^n + 6*R_n - 5 is prime, where R_n = 11...1 is the repunit (A002275) of length n.at n=25A103103
• a(n) is the sum of the lengths of all the segments used to draw a rectangle of height partition(n) and width n divided into partition(n) rectangles of unit height, in turn, divided into rectangles of unit height and lengths corresponding to the parts of the partitions of n.at n=28A338969