Zarankiewicz's problem k_4(n,n+1).A006626Zarankiewicz's problem k_4(n,n+1).Terms a(0) =19a(1) =27a(2) =37a(3) =46a(4) =56a(5) =68a(6) =80a(7) =94a(8) =109External referencesoeis: A006626