8367627

Appears in sequences

• a(n) = A019566(n)/9, where A019566(n) = concat(n,...,1) - concat(1,...,n).at n=7A083449
• Convolution of nonzero repunits (A002275) with themselves.at n=6A272525
• Number of digits '9' in the set of all numbers from 0 to A014824(n) = sum_{i=1..n} i*10^(n-i) = (0, 1, 12, 123, 1234, 12345, ...).at n=8A277849