71515

Appears in sequences

• Hard numbers: a(n) = smallest positive number m with f(m) = n, where f(m) is the smallest number of digits that are needed to construct m using only 1's, 2's and any number of +, -, *, ^ signs, allowing concatenation of the digits.at n=11A060273
• Sum of the sizes of the tails below the Durfee squares of all partitions of n.at n=30A116365
• Integer k associated with the record-breaking number A226663(n) of primitive Collatz-like 3x+k cycles.at n=13A226664