131551domain: NAppears in sequences'Geobonnaci' sequence: a(1)=a(2)=1, thereafter a(n) = round( 2 * sqrt(a(n-1) * a(n-2)) ).at n=26A322332Number of quadrilateral regions in a "frame" of size n X n (see Comments in A331776 for definition), divided by 8.at n=41A332596