User blog comment:Nayuta Ito/Brainfuck challenge/@comment-5529393-20160812091905

BF(15) >= 16 ++++[>++++<-]>. BF(16) >= 20 +++++[>++++<-]>. BF(17) >= 25 +++++[>+++++<-]>. BF(18) >= 30 ++++++[>+++++<-]>. BF(19) >= 36 ++++++[>++++++<-]>. BF(20) >= 42 +++++++[>++++++<-]>. BF(21) >= 49 +++++++[>+++++++<-]>.

and so on...