375598753024domain: NAppears in sequencesBinomial transform of the tribonacci sequence A000073 (shifted left twice).at n=26A117189a(0)=1=a(1), a(2)=2, a(3)=5; thereafter a(n+3)=4*a(n+2)-4*a(n+1)+2*a(n) for n>=1.at n=27A159035