a(n) is the smallest k such that psi(k) = n!, or 0 if no such k exists (psi(k) = A001615(k)).

A291487

a(n) is the smallest k such that psi(k) = n!, or 0 if no such k exists (psi(k) = A001615(k)).

Terms

    a(0) =1a(1) =1a(2) =0a(3) =4a(4) =12a(5) =75a(6) =300a(7) =1950a(8) =13650a(9) =122850a(10) =1160250a(11) =13340250a(12) =140390250a(13) =1825073250a(14) =25318743450a(15) =370489869750

External references