答案
114
解:一串数1,1,1,2,2,3,4,5,7,9,12,16,21,28,…称为帕多瓦数列,根据这个数的规律,
a4=a1+a2,
a5=a2+a3,
因此 a(14)=a(11)+a(12)=12+16=28;
a(15)=a(12)+a(13)=16+21=37;
a(16)=a(13)+a(14)=21+28=49;
a(17)=a(14)+a(15)=28+37=65;
a(18)=a(15)+a(16)=37+49=86;
a(19)=a(16)+a(17)=49+65=114.
故答案为114.