a(n) is the least start of a run of exactly n consecutive powerful numbers (A001694) that are odd, or -1 if no such run exists.

A363192

a(n) is the least start of a run of exactly n consecutive powerful numbers (A001694) that are odd, or -1 if no such run exists.

Terms

    a(0) =1a(1) =25a(2) =2187a(3) =703125a(4) =93096125a(5) =10229709861a(6) =197584409639

External references